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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your Class 11 knowledge and support exam preparation. Choose a topic below to get started.
| 39001. |
A boy and a man carry a uniform pole of length 8 m and of mass 60 kg by supporting it on their shoulders. They are located at the ends of the pole. Where should a load of 90 kg be suspended from boy.s end so that boy carroes only one - third of the total load ? |
| Answer» <html><body><p></p>Solution :The mas of pole acts from its centre .<a href="https://interviewquestions.tuteehub.com/tag/c-7168" style="font-weight:bold;" target="_blank" title="Click to know more about C">C</a>.. Let the load placed at a distance .x. from the <a href="https://interviewquestions.tuteehub.com/tag/boy-903339" style="font-weight:bold;" target="_blank" title="Click to know more about BOY">BOY</a>.s end.<br/><img src="https://doubtnut-static.s.llnwi.net/static/physics_images/AKS_DOC_OBJ_PHY_XI_V01_B_C07_SLV_035_S01.png" width="80%"/><br/>If `N_(1), N_(2)` are the normal <a href="https://interviewquestions.tuteehub.com/tag/reactions-20919" style="font-weight:bold;" target="_blank" title="Click to know more about REACTIONS">REACTIONS</a> on man and boy respectivelt then `N_(1)=(2)/(3)(60+90)g=100 g N`<br/>`N_(2)=(1)/(3)(60+90)g=50g N`<br/><a href="https://interviewquestions.tuteehub.com/tag/taking-1238585" style="font-weight:bold;" target="_blank" title="Click to know more about TAKING">TAKING</a> turning effects about boy.s end .B., we have.<br/>`N_(1)xx8-60g xx 4-90g xx x=0`<br/>or `100 g xx 8-60g xx 4-90g xx x =0`<br/>on solving x = 6.22 m.</body></html> | |
| 39002. |
. Two spheres Pand Qmoving in opposite directions with velocities v_(1)and v_(2) collide with each other. If .e. is the coefficient of restitution, what is their distance of separation at time .t. after collision ? |
| 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/v-722631" style="font-weight:bold;" target="_blank" title="Click to know more about V">V</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>) + V _(<a href="https://interviewquestions.tuteehub.com/tag/2-283658" style="font-weight:bold;" target="_blank" title="Click to know more about 2">2</a>)` <a href="https://interviewquestions.tuteehub.com/tag/te-659599" style="font-weight:bold;" target="_blank" title="Click to know more about TE">TE</a></body></html> | |
| 39003. |
Which of the following pairs of physical quantities have same dimension? |
| Answer» <html><body><p><a href="https://interviewquestions.tuteehub.com/tag/thrust-709467" style="font-weight:bold;" target="_blank" title="Click to know more about THRUST">THRUST</a> and linear <a href="https://interviewquestions.tuteehub.com/tag/momentum-1100588" style="font-weight:bold;" target="_blank" title="Click to know more about MOMENTUM">MOMENTUM</a> <br/>Work and <a href="https://interviewquestions.tuteehub.com/tag/energy-15288" style="font-weight:bold;" target="_blank" title="Click to know more about ENERGY">ENERGY</a> <br/>Work and <a href="https://interviewquestions.tuteehub.com/tag/power-2475" style="font-weight:bold;" target="_blank" title="Click to know more about POWER">POWER</a> <br/>Power and energy</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> | |
| 39004. |
The pressure of air in a constant volume thermometer is 90 cm and 110 cm at 0^@Cand 100^@Crespectively . When the bulb is kept in hot liquids, pressure is 105 cm . Find the temperature of hot liquid. |
| 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/75-334971" style="font-weight:bold;" target="_blank" title="Click to know more about 75">75</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> | |
| 39005. |
A cylindrical container contains water. A cubical block is floating in water with its lower surface connected to a spring. (a) Suppose that the spring is in relaxed state. Now, if the whole contaienr is accelerated vertically upwards. Will the spring get compressed? (b) Suppose that the spring is initially compressed. Now, what will happen to the state of the spring when the container is accelerated upwards? (c) Assume that mass of the block is 1 kg and initially the spring (force constant k=100 N/m) is compressed by 5cm. when the container is accelerated up by an acceleration of 5m//s^(2), the spring has a total compression of 6cm. Calculate the chnag ein volume of block submerged inside water when the container gets accelerated. Density of water is 10^(3) kg//m^(3). |
| Answer» <html><body><p><br/></p>Answer :(a) No <br/> (b) <a href="https://interviewquestions.tuteehub.com/tag/spring-11487" style="font-weight:bold;" target="_blank" title="Click to know more about SPRING">SPRING</a> will <a href="https://interviewquestions.tuteehub.com/tag/get-11812" style="font-weight:bold;" target="_blank" title="Click to know more about GET">GET</a> compressed more <br/> (<a href="https://interviewquestions.tuteehub.com/tag/c-7168" style="font-weight:bold;" target="_blank" title="Click to know more about C">C</a>) `<a href="https://interviewquestions.tuteehub.com/tag/100cm-265929" style="font-weight:bold;" target="_blank" title="Click to know more about 100CM">100CM</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> | |
| 39006. |
Identify the periodic functions and their time periods, if any from the following (i) sin 2t , (ii) sin 3t , (iii) sint + cos t , (iv) sin t + sin 3t (v) e^(-1) |
| 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> :If can be written as `sin <a href="https://interviewquestions.tuteehub.com/tag/2t-301164" style="font-weight:bold;" target="_blank" title="Click to know more about 2T">2T</a> = sin (2t + 2pi) = sin 2(t+ pi)` <br/>Comparing with equation 5.1, time period of given function is `pi` units. <br/>(ii) `sin 3t = sin (3t + 2pi) sin 3 (t+ (2pi)/(3)) therefore ` Time period , `T= (2pi)/(3)` <br/>(iii) After trigonometric transformations, the given functions can be written as<br/>`sin t + <a href="https://interviewquestions.tuteehub.com/tag/cos-935872" style="font-weight:bold;" target="_blank" title="Click to know more about COS">COS</a> t = sqrt2 sin [omega t + pi/4]` , Since it is a sine function , its time period is also `2pi`<br/>Note that the linear combination of time and <a href="https://interviewquestions.tuteehub.com/tag/cosine-936114" style="font-weight:bold;" target="_blank" title="Click to know more about COSINE">COSINE</a> functions , such as `f(t) = A sint + B cost ` is also periodic of time period `2pi` <br/>(<a href="https://interviewquestions.tuteehub.com/tag/iv-501699" style="font-weight:bold;" target="_blank" title="Click to know more about IV">IV</a>) The time period of sin t and sin 3t are `2pi and 2pi//3` as already discussed in above examples . Since the given function can repeat it self only after a time of `2pi` , its time period is `2pi` . <br/>(v)The plot of `e^(-1)` vs t is an shown<br/>From the graph , it is easy to say that the given function is not periodic . <br/> <img src="https://doubtnut-static.s.llnwi.net/static/physics_images/AKS_ELT_AI_PHY_XI_V01_C_C05_SLV_002_S01.png" width="80%"/></body></html> | |
| 39007. |
Is it possible far a body to be accelerated without speeding up or slowing down? If so, give an example |
| Answer» <html><body><p></p>Solution :Yes. An object in <a href="https://interviewquestions.tuteehub.com/tag/uniform-1437485" style="font-weight:bold;" target="_blank" title="Click to know more about UNIFORM">UNIFORM</a> circular <a href="https://interviewquestions.tuteehub.com/tag/motion-1104108" style="font-weight:bold;" target="_blank" title="Click to know more about MOTION">MOTION</a> is <a href="https://interviewquestions.tuteehub.com/tag/accelerating-366486" style="font-weight:bold;" target="_blank" title="Click to know more about ACCELERATING">ACCELERATING</a> but its speed <a href="https://interviewquestions.tuteehub.com/tag/neither-1113494" style="font-weight:bold;" target="_blank" title="Click to know more about NEITHER">NEITHER</a> decreases nor <a href="https://interviewquestions.tuteehub.com/tag/increases-1040626" style="font-weight:bold;" target="_blank" title="Click to know more about INCREASES">INCREASES</a>. (In one dimensional motion it is not possible.)</body></html> | |
| 39008. |
The whirling motion of a stone attached to a string is a .............. motion. |
| Answer» <html><body><p>linear<br/>circular<br/>curvilinear<br/> rotational</p>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> | |
| 39009. |
A polyatomic gas with six degrees of freedom does 25J of work when it is expanded at constant pressure. The heat given to the gas is |
| Answer» <html><body><p><a href="https://interviewquestions.tuteehub.com/tag/100j-265950" style="font-weight:bold;" target="_blank" title="Click to know more about 100J">100J</a> <br/><a href="https://interviewquestions.tuteehub.com/tag/150j-1791949" style="font-weight:bold;" target="_blank" title="Click to know more about 150J">150J</a> <br/><a href="https://interviewquestions.tuteehub.com/tag/200j-290162" style="font-weight:bold;" target="_blank" title="Click to know more about 200J">200J</a> <br/>250J</p>Answer :A</body></html> | |
| 39010. |
Obtain an expression for the excess of pressure inside a (i) liquid drop (ii) liquid bubble (iii) air bubble. |
| Answer» <html><body><p></p>Solution :(i) Liquid drop:Let us consider a liquid drop of radius R and the surface tension of the liquid is T.<br/><img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/PRE_GRG_PHY_XI_V02_C07_E03_009_S01.png" width="80%"/> <br/>The various forces acting on the liquid drop are,<br/>(a) Force due to surface tension `F_(T)=2piRT` towards right<br/>(b) Force due to outside <a href="https://interviewquestions.tuteehub.com/tag/pressure-1164240" style="font-weight:bold;" target="_blank" title="Click to know more about PRESSURE">PRESSURE</a>,`F_(P_1)=P_(1)piR^(2)` towards right<br/>(c) Force due to inside pressure, `F_(P_2)=P_(2)piR^(2)` towards left<br/>As the drop is in equilibrium,<br/>`F_(P_2)=F_(T)+F_(P_1)` <br/>`P_(2)piR^(2)=2piRT+P_(1)piR^(2)` <br/>`rArr(P_(2)-P_(1))piR^(2)=2piRT` <br/>Excess pressure is `DeltaP=P_(2)-P_(1)=(2T)/(R)` <br/>(ii) Liquid bubble:A soap bubble of radius R and the surface tension of the soap bubble be T is as shown in Figure. A soap bubble has two liquid <a href="https://interviewquestions.tuteehub.com/tag/surfaces-1235815" style="font-weight:bold;" target="_blank" title="Click to know more about SURFACES">SURFACES</a> in <a href="https://interviewquestions.tuteehub.com/tag/contact-25916" style="font-weight:bold;" target="_blank" title="Click to know more about CONTACT">CONTACT</a> with air, one inside the bubble and other outside the bubble. Hence, the force on the soap bubble due to surface tension is `2xx2piRT`. The various forces acting on the soap bubble are,<br/><img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/PRE_GRG_PHY_XI_V02_C07_E01_053_S02.png" width="80%"/> <br/>(a) Force due to surface tension `F_(T)=4piRT` towards right<br/>(b) Force due to outside pressure, `F_(P_1)=P_(1)piR^(2)` towards right<br/>(c) Force due to inside pressure, `F_(P_2)=P_(2)piR^(2)` towards left<br/>As the bubble is in equilibrium,<br/>`F_(P_2)=F_(T)+F_(P_1)` <br/>`P_(2)piR^(2)=4piRT+P_(1)piR^(2)` <br/>`rArr(P_(2)-P_(1))piR^(2)=4piRT` <br/>Excess pressure is `DeltaP=P_(2)-P_(1)=(4T)/(R)` <br/>(iii) Air bubble:Let us consider an air bubble of radius R inside a liquid having surface tension T as shown in Figure. Let `P_(1)andP_(2)` be the pressures outside and inside the air bubble, respectively. Now, the excess pressure inside the air bubble is `DeltaP=P_(1)-P_(2)`.<br/><img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/PRE_GRG_PHY_XI_V02_C07_E01_053_S03.png" width="80%"/> <br/>In <a href="https://interviewquestions.tuteehub.com/tag/order-1138220" style="font-weight:bold;" target="_blank" title="Click to know more about ORDER">ORDER</a> to find the excess pressure inside the air bubble, let us consider the forces acting on the air bubble. For the hemispherical portion of the bubble, considering the forces acting on it, we get,<br/>(a) The force due to surface tension acting towards right around the rim of length `2piR` is `F_(T)=2piRT` <br/>(b) The force due to outside pressure `P_(1)` is to the right acting across a cross sectional area of `piR^(2)` is `F_(P_1)=P_(1)piR^(2)` <br/>(c) The force due to pressure `P_(2)` inside the bubble, acting to the left is `F_(P_2)=F_(T)+F_(P_1)` <br/>`P_(2)piR^(2)=2piRT+P_(1)piR^(2)` <br/>`rArr(P_(2)-P_(1))piR^(2)=2piRT` <br/>Excess pressure is `DeltaP=P_(2)-P_(1)=(2T)/(R)`</body></html> | |
| 39011. |
SI unit of Stefan-Boltzmaan constant is. . .. . . . |
| Answer» <html><body><p>`<a href="https://interviewquestions.tuteehub.com/tag/wm-744315" style="font-weight:bold;" target="_blank" title="Click to know more about WM">WM</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>)K^(-4)`<br/>`Wm^(-2)`<br/>`Wm^(-2) K^(-<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/>`Wm^(-2)K^(-2)`<br/></p>Solution :From stefan-Boltzman.s law <br/> `W-A e sigma T^(4)e=1` (<a href="https://interviewquestions.tuteehub.com/tag/emissivity-15409" style="font-weight:bold;" target="_blank" title="Click to know more about EMISSIVITY">EMISSIVITY</a>- unitless) <br/> `:.(W)/(AT^(4)t)= sigma` <br/> `:.` <a href="https://interviewquestions.tuteehub.com/tag/units-1438468" style="font-weight:bold;" target="_blank" title="Click to know more about UNITS">UNITS</a> of `sigma=(J)/(m^(2)K^(4)s)` <br/> `=(W)/(m^(2)K^(-4))`</body></html> | |
| 39012. |
The center of mass is located at position i EX.5.4. Locate the center of mass of a uniform rod of mass M and length |
| Answer» <html><body><p></p>Solution :Consider a uniform <a href="https://interviewquestions.tuteehub.com/tag/rod-1190628" style="font-weight:bold;" target="_blank" title="Click to know more about ROD">ROD</a> of mass M and length / whose one <a href="https://interviewquestions.tuteehub.com/tag/end-971042" style="font-weight:bold;" target="_blank" title="Click to know more about END">END</a> coincides with the origin as shown in Figure. The rod is kept along the x <a href="https://interviewquestions.tuteehub.com/tag/axis-889931" style="font-weight:bold;" target="_blank" title="Click to know more about AXIS">AXIS</a>. To find the <a href="https://interviewquestions.tuteehub.com/tag/center-11455" style="font-weight:bold;" target="_blank" title="Click to know more about CENTER">CENTER</a> of mass of this rod, we choose an infinitesimally small mass dm of elemental length dr at a <a href="https://interviewquestions.tuteehub.com/tag/distance-116" style="font-weight:bold;" target="_blank" title="Click to know more about DISTANCE">DISTANCE</a> from the origin <br/> `lambda`is the linear mass density (ie, mass per unit length) of the rod. `lambda=(M)/(l)` <br/> The mass of small element (dm) is `dm, (M)/(l)dx` <br/> Now, we can write the center of mass equation for this mass distribution as, <br/> `X_(CM)=(int x dxm)/( int dm)` <br/> `X_(CM)=( overset(1) underset(0) intx((M)/(l)dx))/(M)=(1)/(l)overset(1) underset(0) intxdx=(1)/(l)[(x^(2))/(2)]_(0)^(l)=(1)/(l)=((t^(2))/(2))` <br/> `X_(CM)=(l)/(2)` <br/> As the `(l)/(2)` position is the geometric center of the rod, it is concluded that the center of mass <br/> <img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/FM_PHY_XI_V01_C05_SLV_004_S01.png" width="80%"/></body></html> | |
| 39013. |
(A): Always |(d vecv)/(dt)|=(d)/(dt) |vecv|, where vecv has its usual meaning. (R) : Acceleration is rate of change of speed. |
| Answer» <html><body><p>Both (A) and (<a href="https://interviewquestions.tuteehub.com/tag/r-611811" style="font-weight:bold;" target="_blank" title="Click to know more about R">R</a>) are true and (R) is the <a href="https://interviewquestions.tuteehub.com/tag/correct-409949" style="font-weight:bold;" target="_blank" title="Click to know more about CORRECT">CORRECT</a> explanation of (A)<br/>Both (A) and (R) are true and (R) is not the correct explanation of (A)<br/>(A) is true but (R) is false<br/>Both (A) and (R) are false</p>Answer :D</body></html> | |
| 39014. |
What is the value of bulk modulus for an incompressible liquid? |
| 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/infinite-515764" style="font-weight:bold;" target="_blank" title="Click to know more about INFINITE">INFINITE</a>.</body></html> | |
| 39015. |
Three particles A,B,C of mass m each are joined to each other by massless rigid rods to form an equilateral triangle of side a. Another particle of mass m hits B with a velocity v_(0) directed along BC as shown. The colliding particle stops immediately after impact.n The time required by the triangle ABC to complete half revoution in its subsequent motion is (xapi)/(sqrt(3)V_(0)) where 'x' is |
| 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/6-327005" style="font-weight:bold;" target="_blank" title="Click to know more about 6">6</a></body></html> | |
| 39016. |
The gravitational force is always attractive whereas electrostatic force is attractive as well as repulsive. The ratio of electrostatic force and gravitational force between two protons is |
| Answer» <html><body><p>`10^-19`<br/>`10^19`<br/>`10^36`<br/>`10^-36`</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::<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> | |
| 39017. |
A rigid body rotates with an angular momentum L. If its kinetic energy is halved, the angular momentum becomes, |
| Answer» <html><body><p>L<br/>`(L)/(2)`<br/>2L<br/>`(L)/(sqrt(2))`</p>Solution :<a href="https://interviewquestions.tuteehub.com/tag/angular-11524" style="font-weight:bold;" target="_blank" title="Click to know more about ANGULAR">ANGULAR</a> <a href="https://interviewquestions.tuteehub.com/tag/momentum-1100588" style="font-weight:bold;" target="_blank" title="Click to know more about MOMENTUM">MOMENTUM</a>, `L= sqrt(2mE_(K))` <br/> If `E_(K)` is halved `E_(K).= (E_(K))/(2)` <br/> New angular momentum, `L.= 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>._(K))= sqrt((2mE_(K))/(2))` <br/>`L.= (L)/(2)`</body></html> | |
| 39018. |
An electric kettle can heat certain quantity of water from 19°C to 100°C in 6 minutes, time it takes to boil the same quantity of water into steam at 100°C in (minutes) ( L_("steam") = 540 "cal/gm") |
| Answer» <html><body><p>40<br/>30<br/>20<br/>50</p>Answer :A</body></html> | |
| 39019. |
Two projectiles thrown from the same point at angles60^(@)and 30^(@)with the horizontal attain the same height . Which of the following statements is a correct statement ? |
| Answer» <html><body><p>The ratio of their initial velocityies is`sqrt(<a href="https://interviewquestions.tuteehub.com/tag/3-301577" style="font-weight:bold;" target="_blank" title="Click to know more about 3">3</a>)`<br/>The ratio of their initial velocities is`(1)/(sqrt(3))` <br/>The ratio of their initial velocities is 1.<br/>The ratio of their initial velocities is infinity .</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> :`h_("<a href="https://interviewquestions.tuteehub.com/tag/max-546895" style="font-weight:bold;" target="_blank" title="Click to know more about MAX">MAX</a>") = (u^(2) sin^(2) theta)/(2g)`<br/>`h_("max")`is same in both the cases .<br/>`u_(1)^(2) sin^(2)<a href="https://interviewquestions.tuteehub.com/tag/30-304807" style="font-weight:bold;" target="_blank" title="Click to know more about 30">30</a>^(@)`<br/>`(u_(1))/(u_(2)) = (sin 30^(@))/(sin 60^(@))`<br/>`= (1)/(2) <a href="https://interviewquestions.tuteehub.com/tag/xx-747671" style="font-weight:bold;" target="_blank" title="Click to know more about XX">XX</a> (2)/(sqrt(3)) = (1)/(sqrt(3))`</body></html> | |
| 39020. |
A small block of wood of specific gravity 0.5 is subnerged at a depth of 1.2 m in a vessel filled with water. The vessel is accelerated upwards with an acceleration a_(0) = (g)/(2). Time taken by the block to reach the surface, if it is released with zero initial velocity is (g = 10 m//s^(2)) |
| Answer» <html><body><p>0.6 s<br/>0.4 s<br/>1.2 s<br/>1 s</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> | |
| 39021. |
A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the particle. The motion of the particle takes place in a plane. It follows |
| Answer» <html><body><p>its <a href="https://interviewquestions.tuteehub.com/tag/velocity-1444512" style="font-weight:bold;" target="_blank" title="Click to know more about VELOCITY">VELOCITY</a> is <a href="https://interviewquestions.tuteehub.com/tag/constant-930172" style="font-weight:bold;" target="_blank" title="Click to know more about CONSTANT">CONSTANT</a> <br/>its <a href="https://interviewquestions.tuteehub.com/tag/kinetic-533291" style="font-weight:bold;" target="_blank" title="Click to know more about KINETIC">KINETIC</a> energy is constant <br/>its acceleration is constant <br/>it moves in a <a href="https://interviewquestions.tuteehub.com/tag/straight-633156" style="font-weight:bold;" target="_blank" title="Click to know more about STRAIGHT">STRAIGHT</a> <a href="https://interviewquestions.tuteehub.com/tag/line-1074199" style="font-weight:bold;" target="_blank" title="Click to know more about LINE">LINE</a> </p>Answer :B</body></html> | |
| 39022. |
A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the particle. The motion of the particle takes place in a plane. It follows that |
| Answer» <html><body><p>the <a href="https://interviewquestions.tuteehub.com/tag/kinetic-533291" style="font-weight:bold;" target="_blank" title="Click to know more about KINETIC">KINETIC</a> energy of the particle changes with time <br/>the <a href="https://interviewquestions.tuteehub.com/tag/acceleration-13745" style="font-weight:bold;" target="_blank" title="Click to know more about ACCELERATION">ACCELERATION</a> of the particle is <a href="https://interviewquestions.tuteehub.com/tag/constant-930172" style="font-weight:bold;" target="_blank" title="Click to know more about CONSTANT">CONSTANT</a> <br/>the velocity of the particle is constant <br/>the <a href="https://interviewquestions.tuteehub.com/tag/speed-1221896" style="font-weight:bold;" target="_blank" title="Click to know more about SPEED">SPEED</a> of the particle is constant </p>Answer :D</body></html> | |
| 39023. |
Whichof the diagrams in figure correctly shows the change in kinetic energy of an iron sphere falling freely in a lake having sufficient depth to impart it a terminal velocity ? |
| Answer» <html><body><p><img src="https://doubtnut-static.s.llnwi.net/static/physics_images/KPK_AIO_PHY_XI_P1_C06_E04_017_O01.png" width="30%"/><br/><img src="https://doubtnut-static.s.llnwi.net/static/physics_images/KPK_AIO_PHY_XI_P1_C06_E04_017_O02.png" width="30%"/><br/><img src="https://doubtnut-static.s.llnwi.net/static/physics_images/KPK_AIO_PHY_XI_P1_C06_E04_017_O03.png" width="30%"/><br/><img src="https://doubtnut-static.s.llnwi.net/static/physics_images/KPK_AIO_PHY_XI_P1_C06_E04_017_O04.png" width="30%"/></p>Solution :<a href="https://interviewquestions.tuteehub.com/tag/intially-2132834" style="font-weight:bold;" target="_blank" title="Click to know more about INTIALLY">INTIALLY</a> ,velocity of the ironsphere increases and after <a href="https://interviewquestions.tuteehub.com/tag/sometime-7378352" style="font-weight:bold;" target="_blank" title="Click to know more about SOMETIME">SOMETIME</a> becomes constant ,called <a href="https://interviewquestions.tuteehub.com/tag/terminalvelocity-3104224" style="font-weight:bold;" target="_blank" title="Click to know more about TERMINALVELOCITY">TERMINALVELOCITY</a> .Hence ,<a href="https://interviewquestions.tuteehub.com/tag/initially-516121" style="font-weight:bold;" target="_blank" title="Click to know more about INITIALLY">INITIALLY</a> KE increases and then becomes constant which is <a href="https://interviewquestions.tuteehub.com/tag/represented-7262203" style="font-weight:bold;" target="_blank" title="Click to know more about REPRESENTED">REPRESENTED</a> by .</body></html> | |
| 39024. |
Find the depth at which g becomes 4% less than value at surface |
| Answer» <html><body><p>0.2 R<br/>0.04 R<br/>0.3 R<br/>0.03 R</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> | |
| 39025. |
Find the area of the triangle formed by the tips of the vectors vec(a) = hat(i) - hat(j) - 3hat(k), vec(b) = 4hat(i) - 3hat(j) + hat(k) and vec(c ) = 3hat(i) - hat(j) + 2hat(k) |
| Answer» <html><body><p>3.2 sq.units<br/>6.4 sq.units<br/>12.8 sq.units<br/>1.4 sq.units</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> | |
| 39026. |
Prove that DeltaL=10log_(10)[(I_(1))/(I_(0))] decibel, from Weber-Fechner's law. |
| Answer» <html><body><p></p>Solution :According to Weber-Fechner's law, ''loudness (L) is proportional to the logarithm of the actual intensity (I) measured with an accurate non-human instrument''. It is meant that <br/> `LproplnI` <br/> `L=klnI` <br/> The difference between two loudnesses, `L_(1)andL_(0)` <a href="https://interviewquestions.tuteehub.com/tag/measures-1091959" style="font-weight:bold;" target="_blank" title="Click to know more about MEASURES">MEASURES</a> the relative loudness between two precisely measured intensities and is called as sound intensity level. Mathematically, sound intensity level is <br/> `DeltaL=L_(1)-L_(0)=klnI_(1)-klnI_(0)` <br/> `=<a href="https://interviewquestions.tuteehub.com/tag/kln-1063084" style="font-weight:bold;" target="_blank" title="Click to know more about KLN">KLN</a>[(I_(1))/(I_(0))]` <br/> If k=1, then sound intensity level is measured in bel, in <a href="https://interviewquestions.tuteehub.com/tag/honour-487929" style="font-weight:bold;" target="_blank" title="Click to know more about HONOUR">HONOUR</a> of Alexander Graham Bell. <br/> `:.DeltaL=ln[(I_(1))/(I_(0))]`bel <br/> However, this is practically a bigger unit, so we use a convenient smaller unit, called <a href="https://interviewquestions.tuteehub.com/tag/decibel-435735" style="font-weight:bold;" target="_blank" title="Click to know more about DECIBEL">DECIBEL</a>. Thus, decibel `=(1)/(10)bel`. Hence, by multiplying and dividing by 10 we get <br/> `DeltaL=10(ln[(I_(1))/(I_(0))])(1)/(10)bel` <br/> `DeltaL=10ln[(I_(1))/(I_(0))]` decibel with k=10 <br/> For practical purposes, we use logarithm to base 10 instead of natural logarithm, <br/> `DeltaL=10log_(10)[(I_(1))/(I_(0))]` decibel.</body></html> | |
| 39027. |
The density of mercury in egs system is 13.6 g cm^(3). Its value in SI is |
| Answer» <html><body><p>`<a href="https://interviewquestions.tuteehub.com/tag/136-272658" style="font-weight:bold;" target="_blank" title="Click to know more about 136">136</a> kg//m^(<a href="https://interviewquestions.tuteehub.com/tag/3-301577" style="font-weight:bold;" target="_blank" title="Click to know more about 3">3</a>)`<br/>`1360 kg//m^(3)`<br/>`13600kg//m^(3)`<br/>`1.36kg//m^(3)`</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> | |
| 39028. |
A metal rod of length 'L' and maws 'm' is pivoted at one end A thin disc of mass 'M' and radius 'R' ( |
| Answer» <html><body><p> Restoring torque in case A = Restoring torque in case B <br/> Restorings torque in case A lt Restoring torque in case B <br/> Angular frequency for case A gt Angular frequency for case B. <br/> Angular frquency for case A lt Angular frequency for case B. </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> :The fact that disc is free to rotate or not does not affect the forces <a href="https://interviewquestions.tuteehub.com/tag/acting-269" style="font-weight:bold;" target="_blank" title="Click to know more about ACTING">ACTING</a> on the system and hence restoring torque remains same in both the casesso option (a) is correct. <br/> In case A disc is not free to rotate about itscentre hence it has to change its orientation during the oscillation and its moment of inertia as a disc will be counted. But in second case disc will oscillate without changing its orientation andit will be just like a <a href="https://interviewquestions.tuteehub.com/tag/point-1157106" style="font-weight:bold;" target="_blank" title="Click to know more about POINT">POINT</a> mass attached at theend of rod. We can understand that moment of inertia in case A will be more than in case B. Frequency is <a href="https://interviewquestions.tuteehub.com/tag/inversely-7688775" style="font-weight:bold;" target="_blank" title="Click to know more about INVERSELY">INVERSELY</a> proportional to square root of moment of inertia, hence we can understand that option (d) is <a href="https://interviewquestions.tuteehub.com/tag/also-373387" style="font-weight:bold;" target="_blank" title="Click to know more about ALSO">ALSO</a> correct.</body></html> | |
| 39029. |
Can the sum of three vectors, i.e.,their resultant, be equal to zero ? Explain. |
| Answer» <html><body><p></p>Solution :Yes, if the resultant of any <a href="https://interviewquestions.tuteehub.com/tag/two-714195" style="font-weight:bold;" target="_blank" title="Click to know more about TWO">TWO</a> of the vectors is <a href="https://interviewquestions.tuteehub.com/tag/equal-446400" style="font-weight:bold;" target="_blank" title="Click to know more about EQUAL">EQUAL</a> andoppositeto the <a href="https://interviewquestions.tuteehub.com/tag/third-1414358" style="font-weight:bold;" target="_blank" title="Click to know more about THIRD">THIRD</a> one , the resultant of the three vectors will be zero. Let `<a href="https://interviewquestions.tuteehub.com/tag/veca-3257210" style="font-weight:bold;" target="_blank" title="Click to know more about VECA">VECA</a>,vecb,<a href="https://interviewquestions.tuteehub.com/tag/vecc-3257279" style="font-weight:bold;" target="_blank" title="Click to know more about VECC">VECC</a>` bethree vectors related as <br/> `veca+vecb=-vecc`.Then `veca+vecb+vecc=0`</body></html> | |
| 39030. |
The dimensions of 1/2 epsilon E^2. Where epsilon_0 is permittivity of free space and E is electric field is |
| Answer» <html><body><p>`[<a href="https://interviewquestions.tuteehub.com/tag/ml-548251" style="font-weight:bold;" target="_blank" title="Click to know more about ML">ML</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>) T^(-2) ]`<br/>`[ML^(-1) T^(-2) ]`<br/>`[ML^(2) T^(-1) ]`<br/>`[<a href="https://interviewquestions.tuteehub.com/tag/mlt-2163963" style="font-weight:bold;" target="_blank" title="Click to know more about MLT">MLT</a>^(-1) ]`</p>Answer :B</body></html> | |
| 39031. |
The curve between log_(e) L and log_(e) P is (L is the angular momentum and P is the linear momentum). |
| Answer» <html><body><p><img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/PRE_GRG_PHY_XI_V02_C05_E02_033_O01.png" width="30%"/><br/><img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/PRE_GRG_PHY_XI_V02_C05_E02_033_O02.png" width="30%"/><br/><img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/PRE_GRG_PHY_XI_V02_C05_E02_033_O03.png" width="30%"/><br/><img src="https://d10lpgp6xz60nq.cloudfront.net/physics_images/PRE_GRG_PHY_XI_V02_C05_E02_033_O04.png" width="30%"/></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> | |
| 39032. |
A person sitting in a chair in a satellite feels weightless because |
| Answer» <html><body><p> the <a href="https://interviewquestions.tuteehub.com/tag/carth-2501188" style="font-weight:bold;" target="_blank" title="Click to know more about CARTH">CARTH</a> does not attract the objects in a satellite <br/> the normal force by the <a href="https://interviewquestions.tuteehub.com/tag/chair-415628" style="font-weight:bold;" target="_blank" title="Click to know more about CHAIR">CHAIR</a> on the person <a href="https://interviewquestions.tuteehub.com/tag/balances-891822" style="font-weight:bold;" target="_blank" title="Click to know more about BALANCES">BALANCES</a> the earth.s <a href="https://interviewquestions.tuteehub.com/tag/attraction-887653" style="font-weight:bold;" target="_blank" title="Click to know more about ATTRACTION">ATTRACTION</a> <br/> the normal force is zero <br/> the person in satellite is not accelerated</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> | |
| 39033. |
If the earth was a homogeneous sphere and a straight hole was bored through its centre, show that a body dropped into this hole will execute shm. Calculate the time period if the radius of the earth is 6400 km and g = 9.8 ms^(-2) |
| Answer» <html><body><p><br/></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> :At a <a href="https://interviewquestions.tuteehub.com/tag/depth-948801" style="font-weight:bold;" target="_blank" title="Click to know more about DEPTH">DEPTH</a> d,<a href="https://interviewquestions.tuteehub.com/tag/g-1003017" style="font-weight:bold;" target="_blank" title="Click to know more about G">G</a>. `(g//R)(R-d),g.alpha(R-d)` So the <a href="https://interviewquestions.tuteehub.com/tag/motion-1104108" style="font-weight:bold;" target="_blank" title="Click to know more about MOTION">MOTION</a> `T = 2pisqrt("Displacement/accln")` <br/> `T=2pisqrt((R-x))//g.=2pisqrt(R//g)=2pisqrt(6.4xx10^6//9.8)=5079.6`<a href="https://interviewquestions.tuteehub.com/tag/second-1197322" style="font-weight:bold;" target="_blank" title="Click to know more about SECOND">SECOND</a></body></html> | |
| 39034. |
If orbit velocity of planet is given by v = G^(a)M^(b)R^(c), then |
| Answer» <html><body><p>`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>)/(3),b=(1)/(3),c=-(1)/(3)`<br/>`a=(1)/(3),b=(1)/(2),c=-(1)/(2)`<br/>`a=(1)/(2), b=-(1)/(2),c=(1)/(2)`<br/>`a=(1)/(2),b=-(1)/(2),c=-(1)/(2)`</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=sqrt((GM)/(R))=<a href="https://interviewquestions.tuteehub.com/tag/g-1003017" style="font-weight:bold;" target="_blank" title="Click to know more about G">G</a>^(1//2)M^(1//2)R^(-1//2)`</body></html> | |
| 39035. |
The work done by pressure in forcing 2m^(3) of water through a pipe of radius 1 cm, if the pressure difference across a pipe is 10^(5)Pa is |
| Answer» <html><body><p>`<a href="https://interviewquestions.tuteehub.com/tag/3xx10-1865443" style="font-weight:bold;" target="_blank" title="Click to know more about 3XX10">3XX10</a>^(<a href="https://interviewquestions.tuteehub.com/tag/6-327005" style="font-weight:bold;" target="_blank" title="Click to know more about 6">6</a>)<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/>`<a href="https://interviewquestions.tuteehub.com/tag/2xx10-1840192" style="font-weight:bold;" target="_blank" title="Click to know more about 2XX10">2XX10</a>^(5)J`<br/>`4xx10^(6)J`<br/>`0.2xx10^(3)J` </p>Answer :B</body></html> | |
| 39036. |
If a raindrop with a mass of 0.05 g falls with constant velocity, the retarding force of atmospheric frictionis (neglect density of air) …………… . |
| Answer» <html><body><p>zero <br/>49 dynes <br/><a href="https://interviewquestions.tuteehub.com/tag/490-318539" style="font-weight:bold;" target="_blank" title="Click to know more about 490">490</a> dynes <br/>none of these </p>Solution :Since the <a href="https://interviewquestions.tuteehub.com/tag/rain-1176646" style="font-weight:bold;" target="_blank" title="Click to know more about RAIN">RAIN</a> drop is falling with constant velocity , the retarding upwards force is equal to its <a href="https://interviewquestions.tuteehub.com/tag/weight-1451304" style="font-weight:bold;" target="_blank" title="Click to know more about WEIGHT">WEIGHT</a> in magnitude, `F = 0.05 xx <a href="https://interviewquestions.tuteehub.com/tag/980-342886" style="font-weight:bold;" target="_blank" title="Click to know more about 980">980</a> = 49` dynes</body></html> | |
| 39037. |
The length of each rail is 10m. The linear expansion of steel is 12xx10^(-6)//""^(@)C and range of variation of temperature at the given place is 15^(@)C. The gap to be left between the rails is |
| Answer» <html><body><p>0.0018 m<br/>0.0012 m<br/>0.00022 m<br/>0.05 m</p>Answer :A</body></html> | |
| 39038. |
The position of an object moving along x-axis is given by x=a+bt^(2) where a=8.5m, b=2.5ms^(-2) and t is measured in seconds. Then which of the following is true? |
| Answer» <html><body><p><a href="https://interviewquestions.tuteehub.com/tag/velocity-1444512" style="font-weight:bold;" target="_blank" title="Click to know more about VELOCITY">VELOCITY</a> at `t=2` <a href="https://interviewquestions.tuteehub.com/tag/sec-1197209" style="font-weight:bold;" target="_blank" title="Click to know more about SEC">SEC</a> is zero<br/>average velocity between `t=2, t=4` sec is `15m//s`<br/>velocity at `t=4` sec is `10m//s`<br/>all the above are true</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> | |
| 39039. |
A grass hopper can jump maximum distance of 1.6m It spends negligible time on the ground. How far can it go in 10 seconds? |
| 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/u-1435036" style="font-weight:bold;" target="_blank" title="Click to know more about U">U</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>))/(<a href="https://interviewquestions.tuteehub.com/tag/g-1003017" style="font-weight:bold;" target="_blank" title="Click to know more about G">G</a>)=1.6u^(2)=16rArru=`4m/s <br/>`4costheta=4xx(1)/(sqrt(2))=2sqrt(2)//s` <br/> `S=4costheta.t = 2sqrt(2)xx10""S=20sqrt(2)m`</body></html> | |
| 39040. |
(A): If vecr_(1) and vecr_(2) be the initial and final displacement in time vecv_("avg")=(vecr_(2)-vecr_(1))/(t) (R) : The average velocity of a particle having initial and final velocity vecv and vecv_(2) is (vecv_(1)+vecv_(2))/(2), for uniform accelertion |
| Answer» <html><body><p>Both (A) and (<a href="https://interviewquestions.tuteehub.com/tag/r-611811" style="font-weight:bold;" target="_blank" title="Click to know more about R">R</a>) are true and (R) is the <a href="https://interviewquestions.tuteehub.com/tag/correct-409949" style="font-weight:bold;" target="_blank" title="Click to know more about CORRECT">CORRECT</a> <a href="https://interviewquestions.tuteehub.com/tag/explanation-455162" style="font-weight:bold;" target="_blank" title="Click to know more about EXPLANATION">EXPLANATION</a> of (A)<br/>Both (A) and (R) are true and (R) is not the correct explanation of (A)<br/>(A) is true but (R) is false<br/>Both (A) and (R) are false</p>Answer :B</body></html> | |
| 39041. |
An explosion breaks a rock into three parts in a horizontal plane. Two of them go off at right angles to each other. The first part of mass 1 kg moves with a speed of 12 ms^(-1) and the second part of mass 2 kg moves with 8 ms^(-1) speed. If the third part flies off with 4 ms^(-1) speed, then its mass is |
| Answer» <html><body><p>7kg<br/>17kg <br/><a href="https://interviewquestions.tuteehub.com/tag/3-301577" style="font-weight:bold;" target="_blank" title="Click to know more about 3">3</a> <a href="https://interviewquestions.tuteehub.com/tag/kg-1063886" style="font-weight:bold;" target="_blank" title="Click to know more about KG">KG</a> <br/><a href="https://interviewquestions.tuteehub.com/tag/5kg-326499" style="font-weight:bold;" target="_blank" title="Click to know more about 5KG">5KG</a></p>Solution :Thesituationis asshownin thefigureaccordingto lawofconservationoflinearmomemtum<br/> ` vecp_1 + vecp_2 + vecP_3=0 thereforevecP_3 =-vecP_1 + vecP_(2)` <br/>here` vecv_1= ( 1 kg) ( 12 ms^(-1)) <a href="https://interviewquestions.tuteehub.com/tag/hati-2693493" style="font-weight:bold;" target="_blank" title="Click to know more about HATI">HATI</a>= 12 hati kgms^(-)`<br/>` thereforevecP_3 = - (12hati+ 16hatj ) kg ms^(-1) ` <br/> Themagnitudeof `P_3` is<br/> ` P_3 = sqrt((12)^2 + (<a href="https://interviewquestions.tuteehub.com/tag/16-276476" style="font-weight:bold;" target="_blank" title="Click to know more about 16">16</a>)^2) = 20kg ms^(-1)` <br/> ` thereforem_3 = (p_3)/(v_3) =( 20 kg ms^(-1))/(4 ms^(-1)) =5kg `<br/> <img src="https://doubtnut-static.s.llnwi.net/static/physics_images/MTG_NEET_GID_PHY_XI_C03_E03_009_S01.png" width="80%"/></body></html> | |
| 39042. |
What is the slope of graph of stress to strain upto elastic limit? |
| 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/slope-15649" style="font-weight:bold;" target="_blank" title="Click to know more about SLOPE">SLOPE</a> <a href="https://interviewquestions.tuteehub.com/tag/equivalent-446407" style="font-weight:bold;" target="_blank" title="Click to know more about EQUIVALENT">EQUIVALENT</a> to elastic <a href="https://interviewquestions.tuteehub.com/tag/modulus-1100097" style="font-weight:bold;" target="_blank" title="Click to know more about MODULUS">MODULUS</a> of material.</body></html> | |
| 39043. |
Find the load on wire of cross section 16 mm to increase its length by 0.3%(Y=5xx10^(9)N//m^(2),g=10m//s^(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> :`<a href="https://interviewquestions.tuteehub.com/tag/24kg-296320" style="font-weight:bold;" target="_blank" title="Click to know more about 24KG">24KG</a>`</body></html> | |
| 39044. |
Two blocks of masses 10 kg and 30 kg are placed on x - aixs. The first mass is moved on the axis by a distance of 2 cm right. By what distance should the second mass be moved to keep the position of centre of mass unchanged. |
| 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> :mass of the first block, `m_(<a href="https://interviewquestions.tuteehub.com/tag/1-256655" style="font-weight:bold;" target="_blank" title="Click to know more about 1">1</a>)=10 kg`<br/>mass of the second block, `m_(2)=30 kg`<br/>Let `x_(1)` and `x._(1)` are positions of `m_(1)`<br/>`x_(1)` and `x._(1)` are positions of `m_(2)`<br/> <a href="https://interviewquestions.tuteehub.com/tag/initially-516121" style="font-weight:bold;" target="_blank" title="Click to know more about INITIALLY">INITIALLY</a> and later respectively<br/><img src="https://doubtnut-static.s.llnwi.net/static/physics_images/AKS_DOC_OBJ_PHY_XI_V01_B_C07_SLV_005_S01.png" width="80%"/><br/> In this case of `.x_(cm).` is the <a href="https://interviewquestions.tuteehub.com/tag/position-1159826" style="font-weight:bold;" target="_blank" title="Click to know more about POSITION">POSITION</a> of centre of centre of mass then `x_(cm)=(m_(1)x_(1)+m_(2)+x_(2))/(m_(1)+m_(2))`<br/> then the new position of CM when blocks are shifted `x._(cm)=(m_(1)x._(1)+m_(2)x._(2))/(m_(1)+m_(2))`<br/>subtracting the above equations<br/>`x._(cm)-x_(cm)=(m_(1)(x_(1).-x_(1))+m_(2)(x._(2)-x_(2)))/(m_(1)+m_(2))`<br/>`Delta x_(cm)=(m_(1)Delta x_(1)+m_(2)Delta x_(2))/(m_(1)+m_(2))`<br/>`0=(10xx2+30 Delta x_(2))/(40) "" therefore Delta x_(2)=-2//3`<br/>Therefore the second block should be moved left through a distance of 2/3 cm to keep the position of centre of mass <a href="https://interviewquestions.tuteehub.com/tag/unchanged-2316761" style="font-weight:bold;" target="_blank" title="Click to know more about UNCHANGED">UNCHANGED</a>.</body></html> | |
| 39045. |
A shell projected from a level ground has a range R, if it did not explode. At the highest point, the shell explodes into two fragments having masses in the ratio 1 : 2 , with each fragment moving horizontal immediately after the explosion. If the lighter fragment falls at a distance R/2 from the point of projection, behind the point of projection, the distance at which the other fragments falls from the point of projection is |
| Answer» <html><body><p>R/2 <br/>2R/3 <br/>4R/3<br/>7R/4</p>Answer :D</body></html> | |
| 39046. |
If the surface tension of solution of soap in water is 35 dyne/cm, calculate the work done to form an soap bubble of diameter 14 mm with that solution |
| Answer» <html><body><p></p>Solution :Surface tension `S=35` dynes `cm^(-1)=0.035Nm^(-1)` <br/> Radius of the bubble `(<a href="https://interviewquestions.tuteehub.com/tag/r-611811" style="font-weight:bold;" target="_blank" title="Click to know more about R">R</a> )=(14mm)/(<a href="https://interviewquestions.tuteehub.com/tag/2-283658" style="font-weight:bold;" target="_blank" title="Click to know more about 2">2</a>)=7mm` <br/> `=<a href="https://interviewquestions.tuteehub.com/tag/7xx10-1922528" style="font-weight:bold;" target="_blank" title="Click to know more about 7XX10">7XX10</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>)m` <br/> `W=A(S)=8pir^(2)S` <br/> `implies W=8xx(22)/(<a href="https://interviewquestions.tuteehub.com/tag/7-332378" style="font-weight:bold;" target="_blank" title="Click to know more about 7">7</a>)xx49xx10^(-6)xx0.035` <br/> `W=4.312xx10^(-6)J`</body></html> | |
| 39047. |
One end of a long string of linear mass density 8.0 xx 10^(-3) kg m^(-1) is connected to an electrically driven tuning fork of frequency 256Hz. The other end passes over a pulley and is tied to a pan containing a mass of 90kg. The pulley end absorbs all the incoming energy so that reflected waves at this end have negligible amplitude. At t=0, the left end (fork end) of the string x=0 has zero transverse displacement (y=0) and is moving along positive y-direction. The amplitude of the wave is 5.0 cm. Write down the transverse displacement y as function of x and t that describes the wave on the string. |
| Answer» <html><body><p></p>Solution :`y= 0.05 sin (omega t- <a href="https://interviewquestions.tuteehub.com/tag/kx-1064991" style="font-weight:bold;" target="_blank" title="Click to know more about KX">KX</a>) " here " omega = <a href="https://interviewquestions.tuteehub.com/tag/1-256655" style="font-weight:bold;" target="_blank" title="Click to know more about 1">1</a>.61 <a href="https://interviewquestions.tuteehub.com/tag/xx-747671" style="font-weight:bold;" target="_blank" title="Click to know more about XX">XX</a> <a href="https://interviewquestions.tuteehub.com/tag/10-261113" style="font-weight:bold;" target="_blank" title="Click to know more about 10">10</a>^(3) s^(-1), k= 4.84m^(-1), <a href="https://interviewquestions.tuteehub.com/tag/x-746616" style="font-weight:bold;" target="_blank" title="Click to know more about X">X</a> and y` are in m</body></html> | |
| 39048. |
The maximum fractional error in the difference of two quantities is………… |
| Answer» <html><body><p>Z = 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><br/>`DeltaZ = DeltaA -<a href="https://interviewquestions.tuteehub.com/tag/deltab-2053510" style="font-weight:bold;" target="_blank" title="Click to know more about DELTAB">DELTAB</a>`<br/>`(DeltaZ)/(Z) = (DeltaA)/(A) + (DeltaB)/(B)`<br/>`(DeltaZ)/(Z) = (DeltaADeltaB)/(<a href="https://interviewquestions.tuteehub.com/tag/ab-360636" style="font-weight:bold;" target="_blank" title="Click to know more about AB">AB</a>)`</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> :`(DeltaZ)/(Z) = (DeltaA)/(A) + (DeltaB)/(B)`</body></html> | |
| 39049. |
Answer the following questions based on the P-T phase diagram of carbon dioxide: At what temperature and pressure can the solid, liquid and vapour phases ofCO_(2)co-exist in equilibrum ? |
| 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> :At the <a href="https://interviewquestions.tuteehub.com/tag/triple-712945" style="font-weight:bold;" target="_blank" title="Click to know more about TRIPLE">TRIPLE</a> <a href="https://interviewquestions.tuteehub.com/tag/point-1157106" style="font-weight:bold;" target="_blank" title="Click to know more about POINT">POINT</a> temperature ` = - 56.6 ^(@) <a href="https://interviewquestions.tuteehub.com/tag/c-7168" style="font-weight:bold;" target="_blank" title="Click to know more about C">C</a>`and pressure = `5.11` atm.</body></html> | |
| 39050. |
A vertical glass tube closed at the bottom contains mercury to height of 50 cm at 20^(@)C. What will be the height of mercury column at 40^(@)C? (gamma _(Hg (R ))= 18.5 xx 10 ^(-5) //^(@)C and alpha _(g) = 8 xx 10 ^(-6) //^(@)C) |
| 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> :`50.20 <a href="https://interviewquestions.tuteehub.com/tag/cm-919986" style="font-weight:bold;" target="_blank" title="Click to know more about CM">CM</a>`</body></html> | |