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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your Class 12 knowledge and support exam preparation. Choose a topic below to get started.
| 45151. |
A telescope is an optical instrument used to increase the visual angle of distant objects such as stars, planets etc. An astronomical telescope consists of two converging lenses. The one facing the object is called objective and the lens close to the eye is called an eyepiece. It can be adjusted by displacing relative to the objective. The angular magnification is defined as the ratio of focal length of objective and eyepiece. One can see the image with unstrained eye if it forms at infinity. An astronomical telescope has an objective of focal length 50 cm and a magnification of 20. Q Focal length, of the eyepiece is |
| Answer» <html><body><p>2.5 cm<br/>5 cm<br/>7.5 cm<br/>none of these</p>Answer :A</body></html> | |
| 45152. |
Power factor in an L-C-R circuit is …….. |
| Answer» <html><body><p>0<br/>0.5<br/>1<br/>depends on the value of L, <a href="https://interviewquestions.tuteehub.com/tag/c-7168" style="font-weight:bold;" target="_blank" title="Click to know more about C">C</a>, R</p>Solution :Power <a href="https://interviewquestions.tuteehub.com/tag/factor-458892" style="font-weight:bold;" target="_blank" title="Click to know more about FACTOR">FACTOR</a> is given by <br/> `<a href="https://interviewquestions.tuteehub.com/tag/cos-935872" style="font-weight:bold;" target="_blank" title="Click to know more about COS">COS</a> delta=R/sqrt(R^<a href="https://interviewquestions.tuteehub.com/tag/2-283658" style="font-weight:bold;" target="_blank" title="Click to know more about 2">2</a>+(omegaL-1/(omegaC)^2)` <br/> but when <a href="https://interviewquestions.tuteehub.com/tag/resonance-1186596" style="font-weight:bold;" target="_blank" title="Click to know more about RESONANCE">RESONANCE</a> occurs `omegaL=1/(omegaC.)` <br/> `therefore cos delta =R/R=1`</body></html> | |
| 45153. |
Two insulating plates are both uniformly charged in such a way that the potential difference between them is V_(2)-V_(1)=20V. (i.e., plate 2 is at a higher potential). The plates are separated by d = 0.1 m and can be treated infinitely large. An electron is released from rest on the inner surface of plate 1. What is its speed when it hits plate 2? |
| Answer» <html><body><p><br/></p><a href="https://interviewquestions.tuteehub.com/tag/answer-15557" style="font-weight:bold;" target="_blank" title="Click to know more about ANSWER">ANSWER</a> :`2.65xx10^(<a href="https://interviewquestions.tuteehub.com/tag/6-327005" style="font-weight:bold;" target="_blank" title="Click to know more about 6">6</a>) m//s`</body></html> | |
| 45154. |
Figure shows a soap film formed between two square figures made of a uniform wire. The bigger square is held while keeping it in a horizontal plane and the smaller square is slowly allowed to droip vertically. It reaches an equilibrium state after dropping a height h. Let surface tension of soap =T. Mass per unit length of wire =lamda. Acceleration due to gravity =g Given that h=(nlamdaga)/(2sqrt(4T^(2)-lamda^(2)g^(2))), find the integer value n. |
| Answer» <html><body><p><br/></p>Solution :`<a href="https://interviewquestions.tuteehub.com/tag/tantheta-3098264" style="font-weight:bold;" target="_blank" title="Click to know more about TANTHETA">TANTHETA</a>=(<a href="https://interviewquestions.tuteehub.com/tag/3a-310574" style="font-weight:bold;" target="_blank" title="Click to know more about 3A">3A</a>)/(2h)` <br/> `2xx4aTxxcostheta=4alamdag` <br/> `costheta=(lamdag)/(2T)` <br/> `impliesh=(3lamda <a href="https://interviewquestions.tuteehub.com/tag/ga-467684" style="font-weight:bold;" target="_blank" title="Click to know more about GA">GA</a>)/(2sqrt(4T^(2)-<a href="https://interviewquestions.tuteehub.com/tag/lamda-536483" style="font-weight:bold;" target="_blank" title="Click to know more about LAMDA">LAMDA</a>^(2)g^(2)))` <br/> <img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/FIT_JEE_FT3_P2_E01_340_S01.png" width="80%"/></body></html> | |
| 45155. |
The circuit shown in figure, find the current through wire XY in ampere |
| Answer» <html><body><p><br/></p><a href="https://interviewquestions.tuteehub.com/tag/answer-15557" style="font-weight:bold;" target="_blank" title="Click to know more about ANSWER">ANSWER</a> :<a href="https://interviewquestions.tuteehub.com/tag/2-283658" style="font-weight:bold;" target="_blank" title="Click to know more about 2">2</a></body></html> | |
| 45156. |
Find the ratio of magnetic moment of an electron to its angular momentum is an atomic orbit. |
| Answer» <html><body><p></p><a href="https://interviewquestions.tuteehub.com/tag/solution-25781" style="font-weight:bold;" target="_blank" title="Click to know more about SOLUTION">SOLUTION</a> :`(M)/(<a href="https://interviewquestions.tuteehub.com/tag/l-535906" style="font-weight:bold;" target="_blank" title="Click to know more about L">L</a>)=(<a href="https://interviewquestions.tuteehub.com/tag/evr-2065790" style="font-weight:bold;" target="_blank" title="Click to know more about EVR">EVR</a>)/(2xx m <a href="https://interviewquestions.tuteehub.com/tag/v-722631" style="font-weight:bold;" target="_blank" title="Click to know more about V">V</a> r)` <br/> `(M)/(L)=( e )/(2m)`.</body></html> | |
| 45157. |
An air bubble of volume 15 cm is at the bottom of a lake 40 m deep, where the temperature is 4.0^@ C. The bubble rises to the surface, which is at a temperature of 20^@ C Take the temperature of the bubble's air to be the same as that of the surrounding water. Just as the bubble reaches the surface, what is its volume? |
| Answer» <html><body><p></p><a href="https://interviewquestions.tuteehub.com/tag/solution-25781" style="font-weight:bold;" target="_blank" title="Click to know more about SOLUTION">SOLUTION</a> :`<a href="https://interviewquestions.tuteehub.com/tag/77-335698" style="font-weight:bold;" target="_blank" title="Click to know more about 77">77</a> cm^3`</body></html> | |
| 45158. |
In the pervious question ,what is the average velocity of the particle? |
| Answer» <html><body><p>` 1 <a href="https://interviewquestions.tuteehub.com/tag/ms-549331" style="font-weight:bold;" target="_blank" title="Click to know more about MS">MS</a> ^(-1)` <br/>`0.5 ms ^(-1)` <br/>` 3 ms ^(-1)` <br/>None of these </p>Solution : Time taken to go from A to B : ` "" "time "=("distance ")/("speed") =(<a href="https://interviewquestions.tuteehub.com/tag/4-311707" style="font-weight:bold;" target="_blank" title="Click to know more about 4">4</a>)/(1) =4s ` <br/>Average velocity `=("<a href="https://interviewquestions.tuteehub.com/tag/total-711110" style="font-weight:bold;" target="_blank" title="Click to know more about TOTAL">TOTAL</a> displacement ")/("Totaltime")=(<a href="https://interviewquestions.tuteehub.com/tag/2-283658" style="font-weight:bold;" target="_blank" title="Click to know more about 2">2</a>)/(4) =0.5 ms^(-1) `</body></html> | |
| 45159. |
A telescope is an optical instrument used to increase the visual angle of distant objects such as stars, planets etc. An astronomical telescope consists of two converging lenses. The one facing the object is called objective and the lens close to the eye is called an eyepiece. It can be adjusted by displacing relative to the objective. The angular magnification is defined as the ratio of focal length of objective and eyepiece. One can see the image with unstrained eye if it forms at infinity. An astronomical telescope has an objective of focal length 50 cm and a magnification of 20. If object is at a distance 600m from the telescope to see the image with unstrained eye separation between two lenses should be ( in cm ) |
| Answer» <html><body><p>46.65<br/>47.65<br/>49.96<br/>49.65</p>Answer :<a href="https://interviewquestions.tuteehub.com/tag/c-7168" style="font-weight:bold;" target="_blank" title="Click to know more about C">C</a></body></html> | |
| 45160. |
A telescope is an optical instrument used to increase the visual angle of distant objects such as stars, planets etc. An astronomical telescope consists of two converging lenses. The one facing the object is called objective and the lens close to the eye is called an eyepiece. It can be adjusted by displacing relative to the objective. The angular magnification is defined as the ratio of focal length of objective and eyepiece. One can see the image with unstrained eye if it forms at infinity. An astronomical telescope has an objective of focal length 50 cm and a magnification of 20. To view remote object by an unstrainednormal eye separation between two lenses will be |
| Answer» <html><body><p><a href="https://interviewquestions.tuteehub.com/tag/55-325247" style="font-weight:bold;" target="_blank" title="Click to know more about 55">55</a> cm<br/>57.5 cm<br/>60 cm<br/>52.5 cm</p>Answer :D</body></html> | |
| 45161. |
A block of mass 10 kg is moving horizontally with aspeed of 1.5 m s^(-1)on a smooth plane. If a constant vertical force 10 N acts on it, the displacement of the block from the point of application of the force at the end of 4 second is |
| Answer» <html><body><p><a href="https://interviewquestions.tuteehub.com/tag/5-319454" style="font-weight:bold;" target="_blank" title="Click to know more about 5">5</a> m <br/>20 m<br/>12 m <br/>10 m </p>Solution :Here , m=10 <a href="https://interviewquestions.tuteehub.com/tag/kg-1063886" style="font-weight:bold;" target="_blank" title="Click to know more about KG">KG</a> , F= 10 N <br/> The situation is as shown in the figure . <br/> Acceleration along <a href="https://interviewquestions.tuteehub.com/tag/vertical-726181" style="font-weight:bold;" target="_blank" title="Click to know more about VERTICAL">VERTICAL</a> <a href="https://interviewquestions.tuteehub.com/tag/direction-1696" style="font-weight:bold;" target="_blank" title="Click to know more about DIRECTION">DIRECTION</a> <br/> `a_y=F/m ="10 N"/"10 kg" = 1 m s^(-2)` <br/>Distance travelled by the block in <a href="https://interviewquestions.tuteehub.com/tag/4-311707" style="font-weight:bold;" target="_blank" title="Click to know more about 4">4</a> s in vertical direction is <br/> `s_y=1/2a_yt^2=1/2xx(1 m s^(-2) )(4 s)^2`= 8 m <br/> Distance travelled by the block in 4 s in horizontal direction is <br/> `s_x=(1.5 m s^(-1))(4 s)`=6 m <br/> The displacement of the block at the end of 4 s is <br/> `=sqrt(s_x^2+s_y^2)=sqrt((8 m)^2 + (6 m)^2)`= 10 m<br/> <img src="https://doubtnut-static.s.llnwi.net/static/physics_images/MTG_WB_JEE_CHE_MTP_02_E01_006_S01.png" width="80%"/></body></html> | |
| 45162. |
किसी बिंदु-वस्तु (point object) से निकलकर किरणें किसी लेंस से अपवर्तित होकर जिस बिंदु पर मिलती है, उसे कहते हैं |
| Answer» <html><body><p>फोकस<br/>वक्रता-केंद्र<br/>प्रकाश-केद्र<br/>प्रतिबिंब बिंदु</p>Answer :D</body></html> | |
| 45163. |
The electric field at (30, 30) cm due to a charge of -8nC at the origin in NC^(-1) is |
| Answer» <html><body><p>`-400 (<a href="https://interviewquestions.tuteehub.com/tag/bar-892478" style="font-weight:bold;" target="_blank" title="Click to know more about BAR">BAR</a>(i) + bar(<a href="https://interviewquestions.tuteehub.com/tag/j-520843" style="font-weight:bold;" target="_blank" title="Click to know more about J">J</a>))`<br/>`400 (bar(I) + bar(j))`<br/>`-<a href="https://interviewquestions.tuteehub.com/tag/200-288914" style="font-weight:bold;" target="_blank" title="Click to know more about 200">200</a> sqrt2 (bar(i) + bar(j))`<br/>`200 sqrt2 (bar(i) + bar(j))`</p>Answer :<a href="https://interviewquestions.tuteehub.com/tag/c-7168" style="font-weight:bold;" target="_blank" title="Click to know more about C">C</a></body></html> | |
| 45164. |
In the circuit shown, r = 4 Omega, C = 2mu F (a) Find the current coming out of the battery just after the switch is closed(b) Find charge on each capacitor in the steady state condition |
| Answer» <html><body><p></p>Solution :(a) Due to symmetry. the points of equal potential are joined together, and the circuit may be reducedas<br/>`R_(13)=(r)/(2)+(r)/(<a href="https://interviewquestions.tuteehub.com/tag/4-311707" style="font-weight:bold;" target="_blank" title="Click to know more about 4">4</a>)+(r)/(4)+(r)/(2)=(3)/(2)r`<br/>`Here,r=4Omega,R_(13)=(3)/(2)(4)=6omega`<br/><a href="https://interviewquestions.tuteehub.com/tag/thus-2307358" style="font-weight:bold;" target="_blank" title="Click to know more about THUS">THUS</a>,`I=(24)/(R_(13)=(24)/(6)=4A`<br/>(b) in the steady-state condition, the circuit may be reduced as,` R_(13) = 2r = 2(4)Omega = 8Omega`<br/>`I=(24)/(8)=<a href="https://interviewquestions.tuteehub.com/tag/3a-310574" style="font-weight:bold;" target="_blank" title="Click to know more about 3A">3A</a>``V_(56)=(2r)(1)/(2)=Ir=(3)(4)=12V`<br/>Equivalent capacitance between 5 and 6 is<br/>`C_(56)=(<a href="https://interviewquestions.tuteehub.com/tag/c-7168" style="font-weight:bold;" target="_blank" title="Click to know more about C">C</a>)/(2)=1muF`<br/>`thereforeq1_(56)=C_(56)V_(56)=12muC`<br/>NOW,`V_(97)=V_(17)-V_(<a href="https://interviewquestions.tuteehub.com/tag/19-280618" style="font-weight:bold;" target="_blank" title="Click to know more about 19">19</a>)`<br/>`=-r(1)/(2)+2(rl)/(2)=(rl)/(2)=((4)(3))/(2)=6V`<br/>therefore`q_(97)=(2)(6)=12muC`<br/> Similarly, `q_(89) = 12muC`<br/><img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/FIITJEE_PHY_MB_07_C03_SLV_020_S01.png" width="80%"/> <br/><img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/FIITJEE_PHY_MB_07_C03_SLV_020_S02.png" width="80%"/></body></html> | |
| 45165. |
प्रथम 200 प्राकृत संख्याओं का योगफल है |
| Answer» <html><body><p>303600<br/>20100<br/>40200<br/>इनमे से कोई नहीं</p>Answer :<a href="https://interviewquestions.tuteehub.com/tag/b-387190" style="font-weight:bold;" target="_blank" title="Click to know more about B">B</a></body></html> | |
| 45166. |
An electromagnetic wave travels in xy plane making an angle theta with x-axis. Then the equation of the wave is |
| Answer» <html><body><p>`E=E_(<a href="https://interviewquestions.tuteehub.com/tag/0-251616" style="font-weight:bold;" target="_blank" title="Click to know more about 0">0</a>)sin(omegat-kxcos <a href="https://interviewquestions.tuteehub.com/tag/theta-1412757" style="font-weight:bold;" target="_blank" title="Click to know more about THETA">THETA</a>+ky sin theta)`<br/>`E=E_(0)sin(omegat-kx sin theta-ky cos theta)`<br/>`E=E_(0)sin(omegat+kx cos theta+ky sin theta)`<br/>`E=E_(0)sin(<a href="https://interviewquestions.tuteehub.com/tag/omega-585625" style="font-weight:bold;" target="_blank" title="Click to know more about OMEGA">OMEGA</a> t+kx sin theta +ky cos theta)`</p><a href="https://interviewquestions.tuteehub.com/tag/answer-15557" style="font-weight:bold;" target="_blank" title="Click to know more about ANSWER">ANSWER</a> :A</body></html> | |
| 45167. |
If speed of electron emitted becomes double change in wavelength will be ……. |
| Answer» <html><body><p>increased by `(lambda)/(<a href="https://interviewquestions.tuteehub.com/tag/2-283658" style="font-weight:bold;" target="_blank" title="Click to know more about 2">2</a>)`<br/>decrease by `(lambda)/(2)`<br/>increased by 2`lambda`<br/>decreased by `2lambda`</p><a href="https://interviewquestions.tuteehub.com/tag/solution-25781" style="font-weight:bold;" target="_blank" title="Click to know more about SOLUTION">SOLUTION</a> :`v_(2)=2v_(1)` <br/>Kinetic energy of electron `E_(1)=(1)/(2)mv_(1)^(2)` <br/>`E_(2)=(1)/(2)mv_(2)^(2)=(1)/(2)m(2v_(1))^(2)=(1)/(2)m(4v_(1)^(2))` <br/>`therefore E_(2)=4[(1)/(2)mv_(1)^(2)] therefore E_(2)=4E_(1)` <br/> Now `lambda=(h)/(sqrt(<a href="https://interviewquestions.tuteehub.com/tag/2me-1837831" style="font-weight:bold;" target="_blank" title="Click to know more about 2ME">2ME</a>))` <br/>`therefore lambda prop (1)/(sqrt(E))` <br/>`therefore (lambda_(2))/(lambda_(1))=sqrt((E_(1))/(E_(2)))=sqrt((E_(1))/(4E_(1)))=(1)/(2)therefore lambda_(2)=(lambda_(1))/(2)` <br/>`therefore` Decrease in wavelength `lambda_(1)-(lambda_(1))/(2)=(lambda_(1))/(2)`.</body></html> | |
| 45168. |
Light with an energy flux of 18 W//cm^(2) falls on a nonreflecting surface at normal incidence. If the surface has an area of 20 cm^(2), find the average force exerted on the surface during a 30 minute time span. |
| Answer» <html><body><p></p>Solution :The <a href="https://interviewquestions.tuteehub.com/tag/total-711110" style="font-weight:bold;" target="_blank" title="Click to know more about TOTAL">TOTAL</a> energy falling on the surface is <br/> `<a href="https://interviewquestions.tuteehub.com/tag/u-1435036" style="font-weight:bold;" target="_blank" title="Click to know more about U">U</a>=(18 W//cm^(<a href="https://interviewquestions.tuteehub.com/tag/2-283658" style="font-weight:bold;" target="_blank" title="Click to know more about 2">2</a>))xx(20 cm^(2))xx(30xx60 s)` <br/> `=6.48 xx10^(5) J` <br/> Therefore, the total momentum <a href="https://interviewquestions.tuteehub.com/tag/delivered-7259798" style="font-weight:bold;" target="_blank" title="Click to know more about DELIVERED">DELIVERED</a> (for complete absorption) is <br/> `p=(U)/(c )=(6.48xx10^(5) J)/(3xx10^(8) m//s)=2.16 xx10^(-3) kg m//s` <br/> The <a href="https://interviewquestions.tuteehub.com/tag/average-13416" style="font-weight:bold;" target="_blank" title="Click to know more about AVERAGE">AVERAGE</a> force exerted on the surface is <br/> `F=(p)/(t) =(2.16 xx10^(-3)/(0.18xx10^(4))=1.2xx10^(-6) N` <br/> How will your result be modified if the surface is a perfect reflector?</body></html> | |
| 45169. |
Which of the following is the logic symbol of this gate? |
| Answer» <html><body><p> <br/> <img src="https://doubtnut-static.s.llnwi.net/static/physics_images/EXP_SPS_PHY_XII_C14_E06_050_Q01.png" width="30%"/><br/></p><a href="https://interviewquestions.tuteehub.com/tag/answer-15557" style="font-weight:bold;" target="_blank" title="Click to know more about ANSWER">ANSWER</a> :<a href="https://interviewquestions.tuteehub.com/tag/c-7168" style="font-weight:bold;" target="_blank" title="Click to know more about C">C</a></body></html> | |
| 45170. |
Write a note on radioactivity. |
| Answer» <html><body><p></p>Solution :<a href="https://interviewquestions.tuteehub.com/tag/law-184" style="font-weight:bold;" target="_blank" title="Click to know more about LAW">LAW</a> of radioactive decay : <br/> At any instant t , the number of decays per unit time, called rate of decay `((dN)/(dt))` is proportional to the number of nuclei (N) at the same instant. <br/> `(dN)/(dt) infty N` <br/> By introducing a proportionality constant, the relation can be written as<br/> `(dN)/(dt) = lambda N` <br/> Here proportionality constant `lambda` is called decay constant which is different for differentradioactive sample and the negative sign in the equation implies that the N is decreasing withtime. By rewriting the equation (1) we get <br/> `dN = lambda Ndt`...(<a href="https://interviewquestions.tuteehub.com/tag/2-283658" style="font-weight:bold;" target="_blank" title="Click to know more about 2">2</a>)<br/> Here dN represents the number of nuclei decaying in the interval dt. Let <a href="https://interviewquestions.tuteehub.com/tag/us-718298" style="font-weight:bold;" target="_blank" title="Click to know more about US">US</a> assume that at time `t = 0` s, the number of nuclei <a href="https://interviewquestions.tuteehub.com/tag/present-1163722" style="font-weight:bold;" target="_blank" title="Click to know more about PRESENT">PRESENT</a> in the radioactive sample is `N_(0)`. By integratingthe equation (2), we can calculate the number of underdecayed nuclei N at any time t. <br/> From equation (2) we get, <br/> `(dN)/(N) = - lambda dt` ....(3) <br/> `int_(N_(0))^(N) (dN)/(N) = - int_(0)^(t) lambdadt` <br/> `[In N]_(N_(0))^(N) = - lambda t` <br/> `In [(N)/(N_(0))] = - lambdat` <br/> Taking exponentials on both <a href="https://interviewquestions.tuteehub.com/tag/sies-3028721" style="font-weight:bold;" target="_blank" title="Click to know more about SIES">SIES</a>, we get <br/> `N = N_(0)e^(-lambda t)` ...(4) <br/>` [Note : e^(Inx) = e^(y) Rightarrow x = e^(y)]` <br/> <img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/FM_PHY_XII_V02_C08_E01_052_S01.png" width="80%"/> <br/> Equation (4) is called the law of radioactive decay. Here N denotes the number of underdecayednuclei present at any time t and `N_(0)` denotes the number of nuclei at initial time t = 0. Note that the number of atoms is decreasing exponentially over the tie. This implies that the time taken for all the radioactive nuclei to decay will be infinite. Equation(4) is plotted. We can also define another useful quantity called activity (R) or decay rate whichnumber of nuclei decayed per second and it is denoted as `R = |(dN)/(dt)|` <br/> Note : that activity R is a positive quantity. From equation (4), we get <br/> `R = |(dN)/(dt)| = lambda N_(0)e^(-lambdat)` ....(5) <br/> `R = R_(0)e^(-lambdat)` ...(6) <br/> where `R_(0) = lambda N_(0)` <br/> The equation (6) is also equivalent to radioactive law of decay. Here `R_(0)` is the activity of thesample at `t = (0) ` and R is the activity of the sample at any time t. From equation(6), activityalso shows exponential decay behavior. The activity R also can be expressed in terms of number of undecayed atoms present at any time t, From equation(6), since `N = N_(0)e^(-lambdat)` wewrite ` <br/> R = lambda N`...(7)<br/> Equation (4) implies that the activity at any time t is equal to the product of decay constant and number of undecayed nuclei at the same time t. Since N decreases over time, R also decreases.</body></html> | |
| 45171. |
Standard atmosphere pressure is |
| Answer» <html><body><p>a)`76xx13.6xx980cm `of mercury<br/>b)76dyne` <a href="https://interviewquestions.tuteehub.com/tag/cm-919986" style="font-weight:bold;" target="_blank" title="Click to know more about CM">CM</a>^(-<a href="https://interviewquestions.tuteehub.com/tag/2-283658" style="font-weight:bold;" target="_blank" title="Click to know more about 2">2</a>)`<br/>c)`76xx13.6` cm of water coloumn <br/>d)`76xx980` <a href="https://interviewquestions.tuteehub.com/tag/dyne-961313" style="font-weight:bold;" target="_blank" title="Click to know more about DYNE">DYNE</a>` cm^(-2)`</p><a href="https://interviewquestions.tuteehub.com/tag/answer-15557" style="font-weight:bold;" target="_blank" title="Click to know more about ANSWER">ANSWER</a> :C</body></html> | |
| 45172. |
A student makes a short electromagnet by winding 200 turns of wire around a non conducting cylinder of diameter, d= 4 cm . A current of 5 A is passed through the wire . Find the magnetic dipole moment of the device x, xgt gt d , on its axis the magnetic field of the dipole is 4 mu T ? |
| Answer» <html><body><p></p>Solution :Dipole <a href="https://interviewquestions.tuteehub.com/tag/moment-25786" style="font-weight:bold;" target="_blank" title="Click to know more about MOMENT">MOMENT</a> = m = <a href="https://interviewquestions.tuteehub.com/tag/ni-578253" style="font-weight:bold;" target="_blank" title="Click to know more about NI">NI</a> A.] <a href="https://interviewquestions.tuteehub.com/tag/axial-889822" style="font-weight:bold;" target="_blank" title="Click to know more about AXIAL">AXIAL</a> line , `B = (mu_0 <a href="https://interviewquestions.tuteehub.com/tag/2m-300757" style="font-weight:bold;" target="_blank" title="Click to know more about 2M">2M</a>)/(<a href="https://interviewquestions.tuteehub.com/tag/4pi-1882352" style="font-weight:bold;" target="_blank" title="Click to know more about 4PI">4PI</a> x^3)`</body></html> | |
| 45173. |
A coil of wire of radius r has 600 turns and a self inductance of 108 mH. The self inductance of a coil with same radius and 500 turns is |
| Answer» <html><body><p>80mH<br/>75mH<br/>108mH <br/>90mH</p>Solution :Self <a href="https://interviewquestions.tuteehub.com/tag/inductance-1042546" style="font-weight:bold;" target="_blank" title="Click to know more about INDUCTANCE">INDUCTANCE</a> of the coil .<br/> `L=(mu_(0)<a href="https://interviewquestions.tuteehub.com/tag/n-568463" style="font-weight:bold;" target="_blank" title="Click to know more about N">N</a>^(2)pir)/2`<br/> `LpropN^(2)r`<br/>`L_(1)/L_(2)=(N_(1)/N_(2))^(2)(r_(1)/r_(2))`<br/>`implies (<a href="https://interviewquestions.tuteehub.com/tag/108-266746" style="font-weight:bold;" target="_blank" title="Click to know more about 108">108</a>)/(L_(2))=((<a href="https://interviewquestions.tuteehub.com/tag/600-329515" style="font-weight:bold;" target="_blank" title="Click to know more about 600">600</a>)/(500))^2((r)/(r))`<br/> `thereforeL_(2)=75mH.`</body></html> | |
| 45174. |
Hot wire ammeters and voltmeters can be used to measure : |
| Answer» <html><body><p>only <a href="https://interviewquestions.tuteehub.com/tag/alternating-373440" style="font-weight:bold;" target="_blank" title="Click to know more about ALTERNATING">ALTERNATING</a> <a href="https://interviewquestions.tuteehub.com/tag/currents-941646" style="font-weight:bold;" target="_blank" title="Click to know more about CURRENTS">CURRENTS</a> and voltages<br/>both alternating and <a href="https://interviewquestions.tuteehub.com/tag/direct-954477" style="font-weight:bold;" target="_blank" title="Click to know more about DIRECT">DIRECT</a> current and voltages<br/>only direct current and voltages<br/>only thermoelectric currents and voltages </p><a href="https://interviewquestions.tuteehub.com/tag/answer-15557" style="font-weight:bold;" target="_blank" title="Click to know more about ANSWER">ANSWER</a> :B</body></html> | |
| 45175. |
A cylinder of radius r and length L is placed in a uniform electric field in such a way that its axis remains parallel to the electric field. The electric flux passing through the surface of cylinder is |
| Answer» <html><body><p><a href="https://interviewquestions.tuteehub.com/tag/zero-751093" style="font-weight:bold;" target="_blank" title="Click to know more about ZERO">ZERO</a> <br/>`(pir^(2))/E`<br/>`2pir^(2)E`<br/>`(2pir^(2))/E` </p><a href="https://interviewquestions.tuteehub.com/tag/solution-25781" style="font-weight:bold;" target="_blank" title="Click to know more about SOLUTION">SOLUTION</a> :`<a href="https://interviewquestions.tuteehub.com/tag/rarr-1175461" style="font-weight:bold;" target="_blank" title="Click to know more about RARR">RARR</a> phi =<a href="https://interviewquestions.tuteehub.com/tag/vece-3257491" style="font-weight:bold;" target="_blank" title="Click to know more about VECE">VECE</a>. vecA` <br/> `=Eacostheta =<a href="https://interviewquestions.tuteehub.com/tag/ea-444752" style="font-weight:bold;" target="_blank" title="Click to know more about EA">EA</a> cos90^(@)=0`</body></html> | |
| 45176. |
What changes in the current in the range below saturation will take place, if the electrodes of an ionization chamber are brought closer? How will the saturation current change? Plot the current-voltage characteristics for some inter-electrode distance d, and for d_(2)ltd_(1). Assume the other parametersto remain constant. |
| Answer» <html><body><p><br/></p>Solution :Away from the saturation region the <a href="https://interviewquestions.tuteehub.com/tag/current-940804" style="font-weight:bold;" target="_blank" title="Click to know more about CURRENT">CURRENT</a> will increase, <a href="https://interviewquestions.tuteehub.com/tag/since-644476" style="font-weight:bold;" target="_blank" title="Click to know more about SINCE">SINCE</a> the strength of the electric field <a href="https://interviewquestions.tuteehub.com/tag/increases-1040626" style="font-weight:bold;" target="_blank" title="Click to know more about INCREASES">INCREASES</a> as the plates are brought closer together. In conditions of saturation the current will decrease, since the effective volume of the ionization chamber is smaller. The current-voltage characteristics are shown in <a href="https://interviewquestions.tuteehub.com/tag/fig-460913" style="font-weight:bold;" target="_blank" title="Click to know more about FIG">FIG</a>. <br/> <img src="https://doubtnut-static.s.llnwi.net/static/physics_images/ARG_AAP_PIP_PHY_C33_E01_008_S01.png" width="80%"/></body></html> | |
| 45177. |
If r the distance from the centre of the earth, then what is the nature of the graph of gravitational acceleration versus r for point below the earth's surface? |
| Answer» <html><body><p></p><a href="https://interviewquestions.tuteehub.com/tag/solution-25781" style="font-weight:bold;" target="_blank" title="Click to know more about SOLUTION">SOLUTION</a> :A straight line. (For <a href="https://interviewquestions.tuteehub.com/tag/r-611811" style="font-weight:bold;" target="_blank" title="Click to know more about R">R</a> <a href="https://interviewquestions.tuteehub.com/tag/less-1071906" style="font-weight:bold;" target="_blank" title="Click to know more about LESS">LESS</a> than the radius of the Earth, g <a href="https://interviewquestions.tuteehub.com/tag/prop-607409" style="font-weight:bold;" target="_blank" title="Click to know more about PROP">PROP</a> r.)</body></html> | |
| 45178. |
What is Dopper effect ? Obtainan expression for the apparent frequency of sound heard when the source is in motion with respect to an observer at rest. |
| Answer» <html><body><p></p>Solution :Doppler effect `:` The apparent change in the frequency heard by the observer due to the relative motion between the observer and the <a href="https://interviewquestions.tuteehub.com/tag/source-1219297" style="font-weight:bold;" target="_blank" title="Click to know more about SOURCE">SOURCE</a> of sound is calleddopplerd effect. <br/> When a whistling railway engine <a href="https://interviewquestions.tuteehub.com/tag/approaches-882352" style="font-weight:bold;" target="_blank" title="Click to know more about APPROACHES">APPROACHES</a> an observer standing on the platform, the frequency of sound appears to increase. When it moves away the frequency appear to decrease. <br/> <img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/VIK_PHY_QB_C01_E03_005_S01.png" width="80%"/> <br/> Expression for apparent frequency when source is in motion and listener at rest `:` <br/> Let S = Source of sound <br/> O = Listener <br/> Let 'S' be the source, moving with a velocity `'upsilon_(s)'` to wards the stationary listener. <br/> The distance <a href="https://interviewquestions.tuteehub.com/tag/travelled-7256865" style="font-weight:bold;" target="_blank" title="Click to know more about TRAVELLED">TRAVELLED</a> by the source in time period `'T' = upsilon _(s). T ` <br/>Thereforethe successive compressions and rarefactions are drawn closer to listener. <br/> `:. ` Apparent wavelength ` lambda' = lambda - upsilon_(s) T `. <br/> `lambda' = lambda- ( upsilon_(s))/(v) [ :' v = (1)/(T)]` <br/> `= ( lambdav =- upsilon_(s))/( v)= (upsilon-upsilon_(s))/(v)``[ :' v = v lambda ]` <br/>If" v' " is apparent frequency heard by the listener. <br/> then `v'= (upsilon)/( lambda')`where `'upsilon'` is velocity of sound in air. <br/> `v' = (upsilon.v )/( upsilon-v_(s))` <br/> Therefore the apparent frequency is greater than the actual frequency . <br/> Similary , if the sourceis away from the stationary listener thenapparent frequency`v' = ( upsilon.v)/( upsilon+ upsilon_(s))` , which is less than the actual frequency. <br/> <a href="https://interviewquestions.tuteehub.com/tag/limitation-1074036" style="font-weight:bold;" target="_blank" title="Click to know more about LIMITATION">LIMITATION</a> `:` Doppler effectis applicable when the <a href="https://interviewquestions.tuteehub.com/tag/velocities-1444510" style="font-weight:bold;" target="_blank" title="Click to know more about VELOCITIES">VELOCITIES</a> of the source and listener are much less than that of sound velocity.</body></html> | |
| 45179. |
If complex number z(zne2) satisfies the equation z^(2)=4z+|z|^(2)+(16)/(|z|^(3)), then what is the value of |z|^(4) ? |
| Answer» <html><body><p>1<br/>2<br/>4<br/>16</p>Answer :<a href="https://interviewquestions.tuteehub.com/tag/c-7168" style="font-weight:bold;" target="_blank" title="Click to know more about C">C</a></body></html> | |
| 45180. |
In question number 70, what is frequency of photon ? |
| Answer» <html><body><p>`3.1xx10^(15)Hz`<br/>`3.1xx10^(18)Hz`<br/>`9.1xx10^(15)Hz`<br/>`9.1xx10^(18)Hz`</p>Solution :<a href="https://interviewquestions.tuteehub.com/tag/since-644476" style="font-weight:bold;" target="_blank" title="Click to know more about SINCE">SINCE</a>, `<a href="https://interviewquestions.tuteehub.com/tag/upsilon-3249910" style="font-weight:bold;" target="_blank" title="Click to know more about UPSILON">UPSILON</a> =(<a href="https://interviewquestions.tuteehub.com/tag/c-7168" style="font-weight:bold;" target="_blank" title="Click to know more about C">C</a>)/(lambda)` <br/> Here, `c=3xx10^(8)<a href="https://interviewquestions.tuteehub.com/tag/ms-549331" style="font-weight:bold;" target="_blank" title="Click to know more about MS">MS</a>^(-1)`,`lambda=9.7xx10^(-8)m`. <br/> `thereforeupsilon=(3xx10^(8))/(9.7xx10^(-8))=3.1xx10^(15)Hz`.</body></html> | |
| 45181. |
जीवाणु की कोशिका -भित्ति (cell wall) बनी होते है : |
| Answer» <html><body><p>कार्बोहाइड्रेट से<br/>लिपिड से<br/>प्रोटीन से<br/>इन सभी से</p>Answer :D</body></html> | |
| 45182. |
The electric field associated with a light wave is given by E=E_0sin [(1.57xx10^7)(x-ct)] (where x and t are in metre and second respectively ). This light is used in an experiment having work function phi=1.9eV. what is the ejected photoelectron ? [ Take pi=3.14, hc = 12400 eVÅ] |
| Answer» <html><body><p><br/></p><a href="https://interviewquestions.tuteehub.com/tag/answer-15557" style="font-weight:bold;" target="_blank" title="Click to know more about ANSWER">ANSWER</a> :1.2</body></html> | |
| 45183. |
Through two parallel wires A and B, 10 and 2 ampere of currents are passed respectively in oppo-site direction. If the wire A is infinitely long and the length of the wire B is 2m, the force on the conductor B, which is situated at 10cm distance from A will be |
| Answer» <html><body><p>`<a href="https://interviewquestions.tuteehub.com/tag/8xx10-1931283" style="font-weight:bold;" target="_blank" title="Click to know more about 8XX10">8XX10</a>^(-<a href="https://interviewquestions.tuteehub.com/tag/5-319454" style="font-weight:bold;" target="_blank" title="Click to know more about 5">5</a>)N`<br/>`<a href="https://interviewquestions.tuteehub.com/tag/4xx10-1883351" style="font-weight:bold;" target="_blank" title="Click to know more about 4XX10">4XX10</a>^(-5)N`<br/>`4xx10^(-<a href="https://interviewquestions.tuteehub.com/tag/7-332378" style="font-weight:bold;" target="_blank" title="Click to know more about 7">7</a>)N`<br/>`<a href="https://interviewquestions.tuteehub.com/tag/4pixx10-1882366" style="font-weight:bold;" target="_blank" title="Click to know more about 4PIXX10">4PIXX10</a>^(-7)N`</p>Answer :A</body></html> | |
| 45184. |
Obtain on expression for impedance and current in series LCR circuit. Deduce an expression for the resonating frequency of an LCR series reasonating circuit. |
| Answer» <html><body><p></p>Solution :Circuit consists of resistor of <a href="https://interviewquestions.tuteehub.com/tag/resistance-1186351" style="font-weight:bold;" target="_blank" title="Click to know more about RESISTANCE">RESISTANCE</a> R, inductor of inductance L and capacitor of Let i be the current and q be the charge at any instant t. <br/> Back e.m.f across inductor is `-L (di)/(dt)` <br/> and across capacitor is `(-q)/(C )` <br/> <a href="https://interviewquestions.tuteehub.com/tag/total-711110" style="font-weight:bold;" target="_blank" title="Click to know more about TOTAL">TOTAL</a> e.m.f `= V_(m)sin omega t - L (di)/(dt)-(q)/(C )` <br/> <img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/VIK_PHY_QB_C10_E03_001_S01.png" width="80%"/> <br/> According to Ohms law, this must be equal to iR <br/> `V_(m)sin omega t-L(di)/(dt)-(q)/(C )=iR` <br/> `L(di)/(dt)+iR+(q)/(C )=V_(m)sin omega t`.....(1) <br/> The current i any instant in the circuit is <br/> `i=i_(m)sin(omega t - phi)` if `omega L ge (1)/(omega C)` which is <a href="https://interviewquestions.tuteehub.com/tag/possible-592355" style="font-weight:bold;" target="_blank" title="Click to know more about POSSIBLE">POSSIBLE</a> at <a href="https://interviewquestions.tuteehub.com/tag/high-479925" style="font-weight:bold;" target="_blank" title="Click to know more about HIGH">HIGH</a> frequencies. <br/> `i=i_(m)sin(omega t+phi)` if `omega L lt(1)/(omega C)` which is possible at low frequencies. <br/> The maximum current `(i_(m))` is given by<br/> `i_(m)=(V_(m))/(sqrt(R^(2)+((1)/(omega c)-omega L)^(2)))` ....(2) <br/> Its impedance `(Z)=(V_(m))/(i_(m))=sqrt(R^(2)+((1)/(omega C)-omega L)^(2))` ....(3) <br/> Let `phi` be the phase difference between current and e.m.f <br/> `phi = tan^(-1)(((1)/(omega C)-omega L)/(R ))` ....(4)<br/> <a href="https://interviewquestions.tuteehub.com/tag/resonant-2989342" style="font-weight:bold;" target="_blank" title="Click to know more about RESONANT">RESONANT</a> freuency `(f_(0))` : <br/> At this frequency, the impedance of LCR circuit is minimum and is equal to R. At this frequency current is maximum. This frequency is called resonant frequency `(f_(0))`.<br/> At resonance `omega L = (1)/(omega C)` <br/> `omega^(2)=(1)/(LC)` (or) `omega = (1)/(sqrt(LC))` <br/> `2pi f_(0)=(1)/(sqrt(LC))` <br/> `f_(0)=(1)/(2pi sqrt(LC))` <br/> <img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/VIK_PHY_QB_C10_E03_001_S02.png" width="80%"/> <br/> In frequency response curve, at resonant frequency `(f_(0))`, current is maximum. This series resonant circuit is called acceptor circuit.</body></html> | |
| 45185. |
A hemisphere (made of material of refractive index sqrt(3) )of radius ris placed on a horizontal surface with its base touching the surface. A vertical beam of cross sectional radius (sqrt(3))/(2) r is incident symmetrically on its curved surface. Find the radius of the spot of light formed on the horizontal surface |
| Answer» <html><body><p></p><a href="https://interviewquestions.tuteehub.com/tag/solution-25781" style="font-weight:bold;" target="_blank" title="Click to know more about SOLUTION">SOLUTION</a> :`(<a href="https://interviewquestions.tuteehub.com/tag/r-611811" style="font-weight:bold;" target="_blank" title="Click to know more about R">R</a> )/( <a href="https://interviewquestions.tuteehub.com/tag/sqrt-1223129" style="font-weight:bold;" target="_blank" title="Click to know more about SQRT">SQRT</a>(<a href="https://interviewquestions.tuteehub.com/tag/3-301577" style="font-weight:bold;" target="_blank" title="Click to know more about 3">3</a>))`</body></html> | |
| 45186. |
In a Young's experiment, the distance between two slits is 0.2 mm. If the wavelength of light used in this experiment is 5000 Å, then the distance of 3rd bright fringes from central maxima will be ...... |
| Answer» <html><body><p>`0.75`<br/>`0.075`<br/>`0.0075`<br/>`0.057`</p><a href="https://interviewquestions.tuteehub.com/tag/solution-25781" style="font-weight:bold;" target="_blank" title="Click to know more about SOLUTION">SOLUTION</a> :For `<a href="https://interviewquestions.tuteehub.com/tag/n-568463" style="font-weight:bold;" target="_blank" title="Click to know more about N">N</a>^(th)` <a href="https://interviewquestions.tuteehub.com/tag/bright-391129" style="font-weight:bold;" target="_blank" title="Click to know more about BRIGHT">BRIGHT</a>, <a href="https://interviewquestions.tuteehub.com/tag/fringe-1000590" style="font-weight:bold;" target="_blank" title="Click to know more about FRINGE">FRINGE</a>, <br/> In `d sin theta= n lambda` <br/> `n=3, d=0.2 cm lambda=5xx10^(-5) cm` <br/> `:. sin theta=(n lambda)/(d)=(3xx5xx10^(-5))/(0.02)` <br/> `sin theta=(0.015)/(2)=0.0075` <br/> `:. sin theta =0.0075` <a href="https://interviewquestions.tuteehub.com/tag/rad-1175618" style="font-weight:bold;" target="_blank" title="Click to know more about RAD">RAD</a></body></html> | |
| 45187. |
What results exchange of force between neutron and proton due to charged meson. |
| Answer» <html><body><p></p><a href="https://interviewquestions.tuteehub.com/tag/solution-25781" style="font-weight:bold;" target="_blank" title="Click to know more about SOLUTION">SOLUTION</a> :<a href="https://interviewquestions.tuteehub.com/tag/force-22342" style="font-weight:bold;" target="_blank" title="Click to know more about FORCE">FORCE</a> `<a href="https://interviewquestions.tuteehub.com/tag/pto-593453" style="font-weight:bold;" target="_blank" title="Click to know more about PTO">PTO</a> pi+n,<a href="https://interviewquestions.tuteehub.com/tag/nto-1125736" style="font-weight:bold;" target="_blank" title="Click to know more about NTO">NTO</a> p+overset-pi`</body></html> | |
| 45188. |
Hydraulic lift works on the basis of |
| Answer» <html><body><p>Stoke.s Law <br/>Toricelli.s Law <br/>Pascal.s Law <br/>Bernoulli.s Law </p>Solution :<a href="https://interviewquestions.tuteehub.com/tag/hydraulic-493033" style="font-weight:bold;" target="_blank" title="Click to know more about HYDRAULIC">HYDRAULIC</a> <a href="https://interviewquestions.tuteehub.com/tag/lift-1073338" style="font-weight:bold;" target="_blank" title="Click to know more about LIFT">LIFT</a> <a href="https://interviewquestions.tuteehub.com/tag/works-17618" style="font-weight:bold;" target="_blank" title="Click to know more about WORKS">WORKS</a> on the <a href="https://interviewquestions.tuteehub.com/tag/basic-15343" style="font-weight:bold;" target="_blank" title="Click to know more about BASIC">BASIC</a> of Pascal.s law.</body></html> | |
| 45189. |
Derive an expression for the impedance of a series LCR circuit connected to an a.c. supplied to the of variable frequency. Plot a graph showing variation of current with the frequency of the applied voltage. Explain briefly how the phenomenon of resonance in the circuit can be used in the turning mechanism of a radio or TV set. |
| Answer» <html><body><p></p>Solution :<img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/OSW_SP_PHY_XII_C07_E02_017_S01.png" width="80%"/> <br/> Let `V_(L), V_(R ), V_(C )` and V represent the <a href="https://interviewquestions.tuteehub.com/tag/voltage-1447811" style="font-weight:bold;" target="_blank" title="Click to know more about VOLTAGE">VOLTAGE</a> across the inductor resistor capacitor and the source respectively. `V_(R )`is parallel to I. `V_(C )` is `pi//2`behind I and `V_(L)` is `pi//2` ahead of I. <br/> Now <br/> `V_(OR) = V_(OC) = i_(0)X_(C)` and `V_(OL) = I_(0)X_(L)` <br/> <a href="https://interviewquestions.tuteehub.com/tag/clearly-420736" style="font-weight:bold;" target="_blank" title="Click to know more about CLEARLY">CLEARLY</a> `V_(0)^(2) = V_(OR)^(2) + (V_(OL) - V_(OC))^(2)` <br/> `= i_(0)^(2)[R^(2) + (X_(L) - X_(C))^(2)]` <br/> Thus `i_(0) = (V_(0))/(sqrt(R^(2) + (X_(L) - X_(C))^(2))` <br/> Impedance `= (V_(0))/(i_(0)) = sqrt(R^(2) + (X_(L) - X_(C))^(2))` <br/> `= sqrt(R^(2) + (omega L - (1)/(omega C))^(2))` <br/> <img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/OSW_SP_PHY_XII_C07_E02_017_S02.png" width="80%"/> <br/>The capacitance of a capacitor in the turning circuit is varied such that the reason and frequency of the circuit becomes nearly <a href="https://interviewquestions.tuteehub.com/tag/equal-446400" style="font-weight:bold;" target="_blank" title="Click to know more about EQUAL">EQUAL</a> to the frequency of the radio signal to be received. When this happens the amplitude of the <a href="https://interviewquestions.tuteehub.com/tag/current-940804" style="font-weight:bold;" target="_blank" title="Click to know more about CURRENT">CURRENT</a> becomes <a href="https://interviewquestions.tuteehub.com/tag/maximum-556915" style="font-weight:bold;" target="_blank" title="Click to know more about MAXIMUM">MAXIMUM</a> in the receiving circuit.</body></html> | |
| 45190. |
An aeroplane flies along a straight line from A to B with a speed y, and back again with the same speed v_(0). A steady wind v_(0) is blowing. If AB=1 then total time for the trips is (2v_(0)l)/(v_(0)^(2)-v^(2)) if wind blows along the line AB total tiem for the trip is (2l)/(sqrt(v_(0)^(2)-v^(2))), if wind blows perpendicular to the line AB total time for the trip decrease because of the presence of wind total time for the trip increase because of the presence of wind |
| Answer» <html><body><p>a, <a href="https://interviewquestions.tuteehub.com/tag/b-387190" style="font-weight:bold;" target="_blank" title="Click to know more about B">B</a>, d are <a href="https://interviewquestions.tuteehub.com/tag/correct-409949" style="font-weight:bold;" target="_blank" title="Click to know more about CORRECT">CORRECT</a><br/>a, b, <a href="https://interviewquestions.tuteehub.com/tag/c-7168" style="font-weight:bold;" target="_blank" title="Click to know more about C">C</a> are correct<br/>only a, d are correct<br/>only b, d are correct <a href="https://interviewquestions.tuteehub.com/tag/relative-1183377" style="font-weight:bold;" target="_blank" title="Click to know more about RELATIVE">RELATIVE</a> velocity</p>Answer :A</body></html> | |
| 45191. |
An electric bulb rated for 500 watt at 100 volt is used in a circuit having a 200 volt supply. The resistance R that must be put in series with the bulb, so that the bulb delivers 500 watt is ……….. Ohm. |
| Answer» <html><body><p><<a href="https://interviewquestions.tuteehub.com/tag/p-588962" style="font-weight:bold;" target="_blank" title="Click to know more about P">P</a>></p>Solution :Resistance of the bulb <br/> <img src="https://doubtnut-static.s.llnwi.net/static/physics_images/AKS_DOC_OBJ_PHY_XII_V02_B_C03_SLV_047_S01.png" width="80%"/> <br/> `R_(0)=(V_(0)^(2))/(P_(0))=(100xx100)/(<a href="https://interviewquestions.tuteehub.com/tag/500-323288" style="font-weight:bold;" target="_blank" title="Click to know more about 500">500</a>)=20Omega` <br/> To deliver 500 W long the given bulb 100 V P.d. must drop at the bulb. As the given source has emf 200 V, remaining 100 V P.D. must drop at the resistance R. As the potential <a href="https://interviewquestions.tuteehub.com/tag/differences-951427" style="font-weight:bold;" target="_blank" title="Click to know more about DIFFERENCES">DIFFERENCES</a> are <a href="https://interviewquestions.tuteehub.com/tag/equal-446400" style="font-weight:bold;" target="_blank" title="Click to know more about EQUAL">EQUAL</a> across `R and R_(0)` and they are in series, `R=R_(0)` <br/> `therefore R=20Omega`</body></html> | |
| 45192. |
A spherical shell of mass 20 kg is stationary at the top of a hill of height 100 m. It rolls down a smooth surface to the ground, then climbs up another hill of height 30 m and finally rolls down to a horizontal base at a height of 20 m above, the ground. The velocity attained by the ball is : |
| Answer» <html><body><p>`40 m//s`<br/>`20 m//s`<br/> `10 m//s`<br/>`10sqrt(30 )m//s`</p><a href="https://interviewquestions.tuteehub.com/tag/solution-25781" style="font-weight:bold;" target="_blank" title="Click to know more about SOLUTION">SOLUTION</a> :Loss in potential energy = Gain in K.E.<br/>`<a href="https://interviewquestions.tuteehub.com/tag/mg-1095425" style="font-weight:bold;" target="_blank" title="Click to know more about MG">MG</a> <a href="https://interviewquestions.tuteehub.com/tag/xx-747671" style="font-weight:bold;" target="_blank" title="Click to know more about XX">XX</a> 80 = (1)/(2)mupsilon^(2)`<br/>` <a href="https://interviewquestions.tuteehub.com/tag/implies-1037962" style="font-weight:bold;" target="_blank" title="Click to know more about IMPLIES">IMPLIES</a> upsilon^(2) = 2 xx 10 xx 80 = 1600`<br/>`impliesu= 40 m//s`<br/> <a href="https://interviewquestions.tuteehub.com/tag/hence-484344" style="font-weight:bold;" target="_blank" title="Click to know more about HENCE">HENCE</a> choice is (a).</body></html> | |
| 45193. |
In the above problem, find the ratio of frequencies of wave |
| Answer» <html><body><p>`(M)/(M + m)` <br/>`<a href="https://interviewquestions.tuteehub.com/tag/sqrt-1223129" style="font-weight:bold;" target="_blank" title="Click to know more about SQRT">SQRT</a>((M)/(M+ m))` <br/><a href="https://interviewquestions.tuteehub.com/tag/1-256655" style="font-weight:bold;" target="_blank" title="Click to know more about 1">1</a><br/>`(m)/(M + m)` </p><a href="https://interviewquestions.tuteehub.com/tag/answer-15557" style="font-weight:bold;" target="_blank" title="Click to know more about ANSWER">ANSWER</a> :<a href="https://interviewquestions.tuteehub.com/tag/c-7168" style="font-weight:bold;" target="_blank" title="Click to know more about C">C</a></body></html> | |
| 45194. |
A radioactive nucleus undergoes a series of decays according to the sequence A overset(beta)rarrA_(1)overset(alpha)rarrA_(2) overset(alpha)rarrA_(3).If the mass number and atomic number of A3 are 172 and 69 respectively, what is the mass number and atomic number of A? |
| Answer» <html><body><p> <a href="https://interviewquestions.tuteehub.com/tag/180-279527" style="font-weight:bold;" target="_blank" title="Click to know more about 180">180</a>, 72<br/> 180, <a href="https://interviewquestions.tuteehub.com/tag/74-334795" style="font-weight:bold;" target="_blank" title="Click to know more about 74">74</a> <br/> <a href="https://interviewquestions.tuteehub.com/tag/176-1796981" style="font-weight:bold;" target="_blank" title="Click to know more about 176">176</a>, 72<br/> <a href="https://interviewquestions.tuteehub.com/tag/170-278357" style="font-weight:bold;" target="_blank" title="Click to know more about 170">170</a>, <a href="https://interviewquestions.tuteehub.com/tag/70-333629" style="font-weight:bold;" target="_blank" title="Click to know more about 70">70</a> </p>Answer :A</body></html> | |
| 45195. |
Two equal positive charges are kept at points A and B. The electric potencial at the points between A and B (excluding these points) is studied while moving from A to B The potential |
| Answer» <html><body><p>contiuously increases<br/>continuously decreases<br/>increases then decreases<br/>decreases then increases</p>Answer :D</body></html> | |
| 45196. |
A tuning fork produces a wave of wavelength 110 cm in air at 0°C. The wavelength at 25°C would be |
| Answer» <html><body><p><a href="https://interviewquestions.tuteehub.com/tag/110-268165" style="font-weight:bold;" target="_blank" title="Click to know more about 110">110</a> <a href="https://interviewquestions.tuteehub.com/tag/cm-919986" style="font-weight:bold;" target="_blank" title="Click to know more about CM">CM</a><br/>115 cm<br/>120 cm<br/>130 cm </p><a href="https://interviewquestions.tuteehub.com/tag/answer-15557" style="font-weight:bold;" target="_blank" title="Click to know more about ANSWER">ANSWER</a> :<a href="https://interviewquestions.tuteehub.com/tag/b-387190" style="font-weight:bold;" target="_blank" title="Click to know more about B">B</a></body></html> | |
| 45197. |
Current sensivity of galvanometer in inversely proportional to…… |
| Answer» <html><body><p>number of <a href="https://interviewquestions.tuteehub.com/tag/turns-1429088" style="font-weight:bold;" target="_blank" title="Click to know more about TURNS">TURNS</a> <br/>torsional constant <br/>area<br/>magnetic field</p>Solution :<a href="https://interviewquestions.tuteehub.com/tag/current-940804" style="font-weight:bold;" target="_blank" title="Click to know more about CURRENT">CURRENT</a> sensitivity of galvanometer, <br/> `phi/I=(<a href="https://interviewquestions.tuteehub.com/tag/nab-569140" style="font-weight:bold;" target="_blank" title="Click to know more about NAB">NAB</a>)/k""`[k = torsional constant]</body></html> | |
| 45198. |
State the potentiometer principle. |
| Answer» <html><body><p></p>Solution :Potential difference between two <a href="https://interviewquestions.tuteehub.com/tag/points-1157347" style="font-weight:bold;" target="_blank" title="Click to know more about POINTS">POINTS</a> of a <a href="https://interviewquestions.tuteehub.com/tag/current-940804" style="font-weight:bold;" target="_blank" title="Click to know more about CURRENT">CURRENT</a> carrying conductos is directly <a href="https://interviewquestions.tuteehub.com/tag/proportional-1170279" style="font-weight:bold;" target="_blank" title="Click to know more about PROPORTIONAL">PROPORTIONAL</a> to the <a href="https://interviewquestions.tuteehub.com/tag/length-1071524" style="font-weight:bold;" target="_blank" title="Click to know more about LENGTH">LENGTH</a> of the wire between two points.</body></html> | |
| 45199. |
The sound waves after being converted into electrical waves are not transmitted as such because |
| Answer» <html><body><p>they travel with the speed of <a href="https://interviewquestions.tuteehub.com/tag/sound-648690" style="font-weight:bold;" target="_blank" title="Click to know more about SOUND">SOUND</a> <br/>the frequency is not constant <br/>they are heavily absorbed by the atmosphere<br/>the <a href="https://interviewquestions.tuteehub.com/tag/height-1017806" style="font-weight:bold;" target="_blank" title="Click to know more about HEIGHT">HEIGHT</a> of antenna has to be increased several times </p><a href="https://interviewquestions.tuteehub.com/tag/answer-15557" style="font-weight:bold;" target="_blank" title="Click to know more about ANSWER">ANSWER</a> :C</body></html> | |
| 45200. |
Consider two conducting spheres of radii R_(1) and R_(2) with R_(1) gt R_(2). If the two are at same potential, the larger sphere has more charge than the smaller sphere, then charge density of the smaller sphere is more than that of the larger one. |
| Answer» <html><body><p><br/></p><a href="https://interviewquestions.tuteehub.com/tag/answer-15557" style="font-weight:bold;" target="_blank" title="Click to know more about ANSWER">ANSWER</a> :<a href="https://interviewquestions.tuteehub.com/tag/1-256655" style="font-weight:bold;" target="_blank" title="Click to know more about 1">1</a></body></html> | |