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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 38501. |
चतुष्कोणीय (tetragonal ) क्रिस्टल तन्त्र में निम्नलिखित इकाई सैल आयाम होते हैं |
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Answer» `a=B=C` तथा`alpha=beta=gamma=90^(@)` |
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| 38502. |
Express the equation of a simple harmonic progressive wave in terms of (i) wavelength and period of wave (ii) wavelength and wave speed. |
| Answer» SOLUTION :(i) `y=Asin2pi(t/T-x/LAMDA) (II) y=Asin(2PI)/(lamda)(vt-x)`. | |
| 38503. |
Heavy water is used in nuclear reactors |
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Answer» to absorb neutrons to sustain controlled reaction |
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| 38505. |
What's logic gate ? Why so named ? |
| Answer» Solution :As logic GATE FOLLOWS a certain LOGICAL RELATIONSHIP. | |
| 38506. |
What should be the resistivity of materials for electromagnetism ? |
| Answer» Solution :Higher, LESS LOSSES due to LOWER EDDY current | |
| 38507. |
Show that the radius of the orbit in hydrogen atom varies as n^(2), where it is the principal quantum number of the atom. |
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Answer» Solution :We know that when an electron revolves in a stable orbit, the centripetal force is provided by electrostatic force of attraction acting on it due to a proton present in the nucleus. `THEREFORE""(m v_(n)^(2))/(r_(n)) = (1)/(4pi in_(0)) .(E^(2))/(r_(n)^(2))or v_(n) = (nh)/( 2pi m r_(n))"".....(i)` andfromBohr.s quantum condition , we have . `m v_(n) r_(n) =(n h)/(2 pi) or v_(n) =(n h)/( n h)/(4 pi in_(0) m r_(n))""........(ii) ` SQUARING(ii) and then equatingit with (i) , we get . `(n^(2)h^(2))/(4 pi^(2) m^(2) r_(n)^(2)) = (e^(2))/(4 pi in_(0) m.r_(n))rArrr_(n) = (n^(2) h^(2))/(4pi^(2) m^(2)) xx (4 pi in_(0) m)/(e^(2)) = ( in_(0)h^(2))/( pi m e^(2)) = n^(2)` In stable orbitof hydrogen atom n = 1and then radiusof 1ST orbitis CALLED Bohr.sradius`a_(0)` . Obviously ` a_(0)= (in_(0) h^(2))/(pi m e^(2))` |
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| 38508. |
The limiting angle of incidence for emergent ray is |
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Answer» `30^(@)` |
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| 38509. |
(A): Heavy water absorbs neutrons more efficiently than normal water. (R) : Heavy water has more molecular mass than normal water. |
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Answer» Both .A. and .R. are TRUE and .R. is the CORRECT explanation of .A. |
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| 38510. |
A tangent galvanometer has coil of 50 turns and mean diameter of 22cm. The current through it when the needle is deflected through 60^@ at a place where horizontal component of earth is B_H= 30 mu Tis |
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Answer» `300 mA` |
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| 38511. |
Obtain the equivalent capacitance of the network in Fig. 2.33. For a 300 V supply, determine the charge and voltage across each capacitor. |
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Answer» SOLUTION :EQUIVALENT capacitance = (200/3) pF. `Q_(1) = 10^(-8) C, V_(1) = 100 V: Q_(2) = Q_(3) = 10^(-8)` C `V_(2) =V_(3) = 50 V` `Q_(4) = 2.55 xx 10^(-8) C, V_(4) = 200 V` |
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| 38512. |
A slit 4 cm wide is irradiated with microwaves of wavelength 2 cm. Find the angular spread of central maxima assuming incidence normal to the plane of the slit. |
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Answer» |
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| 38513. |
(A): The order of accuracy of a measurement depends on the least count of the instrument. (R): The smaller the least count, more number of significant figures are in the measured value. |
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Answer» Both (A) and (R) are TRUE and (R) is the CORRECT explanation of (A) |
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| 38514. |
A massive horizontal platform is moving horizontally with a constant acceleration of 10 m//s^(2) as shown in the figure. A particle P of mass m=1kg is kept at rest at the smooth surface as shown in the figure. The particle is hinged at O with the help of a massless rod OP of length 0.9 m. Hinge O is fixed on the platform and the rod can freely rotate about point O. Now the particle P is imparted a velocity in the opposite direction of the platform's acceleration such that it is just able to complete the circular motion about point O. Then the maximum tension appearing in the rod during the motion is 10n. Find the value of n. |
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Answer» <P> SOLUTION :Required velocity of `P` for completing the cycle at the instant, when `OP` is along the direction of motion of PLATFORM is`v_(min)=sqrt(4xx10xx0.9)=6m//s` So `T-ma=(mv_(min)^(2))/(L)` `T=10+((1)36)/(0.9)=10+40=50N` |
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| 38515. |
Ohm's Law is not obeyed by |
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Answer» ELECTROLYTES |
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| 38516. |
The potenital difference between the terminals of a 6.0 V battery is 7.2 V when it is being charged by a current of 2.0 A. What is the internal resistance of the resistor. |
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Answer» |
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| 38517. |
A concave mirror of radius of curvature 40 cm is placed at the bottom of a tank of water (mu= 4//3) with its optic axis vertical and the mirror facing upward. Find the position of the image of a bird flying over the tank at a height 60 cm above the surface of water, which is 20 cm deep. |
| Answer» SOLUTION :3.75 CM about the WATER SURFACE | |
| 38518. |
A body is thrown vertically upward from a point 'A' 125 m above the ground .It goes up to a maximum height of 250 m above the ground and passes through 'A' on its downward journey .The velocity of the body when it is at a height of 70 m above the ground is (g=10ms^(-2)) |
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Answer» `50ms^(-1)` |
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| 38519. |
In a series C–R circuit, applied voltage is V = 110 sin 314t volt. What is the (i) The peak voltage (ii) Average voltage over half cycle ? |
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Answer» SOLUTION :(i) `V_(0) = 110` Volt (ii) `V_("AV"1//2) = (2V_(0))/(PI) = (2xx 110 xx 7)/(22) = 70` volt. |
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| 38520. |
2 mole NaOH is dissolved in 2 L solution , Molarity of solution is …… |
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Answer» 2 M |
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| 38521. |
A horizontal straight wire 10 m long extending from east to west is falling with a speed of 5.0 "m s"^(-1), at right angles to the horizontal component of the earth's magnetic field, 0.30 xx 10^(-4) "Wb m"^(-2). (a) What is the instantaneous value of the emf induced in the wire ? (b) What is the direction of the emf ? (c) Which end of the wire is at the higher electrical potential ? |
| Answer» SOLUTION :`1.5 xx 10^(-3)V, (b) ` WEST to East , (C) Eastern end. | |
| 38522. |
Two bodies of masses 15gm and 25gm are connected by means of a string of length 40cm and mass 10 gm. The string is made to pass over a smooth massless pulley. Initially the two bodies are kept at the same level and released. By the time the heavier mass descends by 10cm, the acceleration of the system: |
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Answer» REMAINS constant |
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| 38523. |
सही कथन बताएँ- |
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Answer» दो सजातीय आवेशों के बीच आकर्षण-बल दोनों आवेशों के बीच की दूरी का व्युत्क्रमानुपाती होता है। |
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| 38524. |
Anexperimenter measure the length of a rod . Initially the experiment and the rod are at rest with respect to the lab. Consider the following statements. |
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Answer» A is true but B is false |
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| 38525. |
A particle of mass m is executing S.H.M. about the origin along x-axis. The P.E. U(x)=kx^(3), where k is +ve constant. If the amplitude of oscillation is 'a', then time period T is proportional to : |
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Answer» `(1)/(SQRT(a))` |
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| 38526. |
A vertical automobile radio antenna is senitive to electric fields that are polarized |
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Answer» Horizontally |
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| 38527. |
The tones thatare separated by three octaves havea frequency ratio of |
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Answer» 3 |
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| 38528. |
A force of F = 12.0 N is applied to a 8.00 kg block at a downward angle of 30^(@) as shown in the figure. The coefficient of static friction between the block and the floor is 0.700 and the coefficient of kinetic friction is 0.400. What is the magnitude of the frictional force on the block? |
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Answer» 19 N |
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| 38529. |
11 kW of electric power can be transmitted to a distant station at (i) 220 V or (ii) 22,000 V. Which of the two modes of transmission should be preferred and why ? Support your answer with possible calculations. |
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Answer» Solution : We shall prefer transmission of power to a distant STATION at 22,000 V in order to minimise power loss due to Joule.s heating during transmission. To explain it, let US PRESUME that resistance of transmission line be `R OMEGA`. When 11 kW (or `11 xx 10^(3)` W) power is transmitted at 220 V, line current `I = P/V = (11 xx 10^(3))/220 = 50 A` and power loss `=I^(2)R = (50)^(2) R = 2500 RW` However, when same power is transmitted at 22,000 V, the line current `I. = P/(V.) = (11 xx 10^(3))/(22,000) = 1/2 A = 0.5 A` Hence, power ions now `=I^(2) R = (0.5)^(2) xx R = 0.25 R W`. From above calculations, it is self-evident that the power loss in second option is negligible and THEREFORE we prefer this mode of power transmission. |
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| 38530. |
What mu is called ? |
| Answer» SOLUTION :ABSOLUTE REFRACTIVE INDEX | |
| 38531. |
One train is approaching an observer at rest and another train is receding him with same velocity 4 ms^(-1). Both the trains blow whistles of same frequency of 243 Hz. The beat frequency in Hz as heard by the observer is (speed of sound in air=320 ms^(-1)) |
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Answer» |
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| 38532. |
What are two pratical forms of Wheatstone bridge ? |
| Answer» Solution :SLIDE wire BRIDGE and post office BOX. | |
| 38533. |
Suppose India a target of producing by 2020 AD, 2,00,000 MW of electric power, ten percent of which was to be obtained from nuclear power plants. Suppose we are given that, on an average, the efficiency of utilization i.e. conversion to electric energy. of thermal energy produced in a reactor was 25%. How much amount of fissionable uranium would our country need per year by 2020 ? Take the heat energy per fission of .^(235)U to be about 200 MeV. |
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Answer» Solution :Total targeted power `= 2xx10^(5)MW` Total Nuclear power = 10% of `2xx10^(5)MW` `= 2xx10^(4)MW` Energy produced in fission = 200 MeV EFFECIENCY of power plant = 25% `therefore` Energy converted into electrical energy per fission `= (25)/(100)xx200=50 MeV` `= 50xx1.6xx10^(-13)` Joule. Total electrical energy to be produced `= 2xx10^(4)MW = 2xx10^(4)xx10^(6)` Watt `= 2xx10^(10)` Joule/Sec `= 2xx10^(10)xx60xx60xx24xx365` Joule/year No. of FISSIONS in one year `= (2xx10^(10)xx60xx60xx24xx365)/(50xx1.6xx10^(-13))` `=2xx(36xx24xx365)/(8)xx10^(24)` Mass of `6.023xx10^(23)` ATOMS of `U^(235)= 235 gm = 235xx10^(-3)kg` Mass of `(2xx36xx24xx365)/(8)xx10^(24)` atoms `= (235xx10^(-3))/(6.023xx10^(23))xx(2xx36xx24xx365xx20^(24))/(8)` `= 3.08xx10^(4)` Kg. Hence mass of Uranium needed per year `= 3.08xx10^(4) Kg`. |
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| 38534. |
The square shown is the same size is each of the following diagrams. In which diagram is the electrical potential energy of the pair of charges the greatest? |
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Answer»
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| 38535. |
Light is incident normally on face AB of a prism as shown in figure. A liquid of refractive index u is placed on face AC of the prism. The prism is made of glass of refractive index 3/2. The limits of mu for which total internal reflection takes place on face AC is |
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Answer» SOLUTION :Critical angle between glass and liquid face is `sin theta_C = (mu )/(3/2)= ( 2MU )/(3) ` Angle of INCIDENCE at face AC is `60^@`.  For the TIR to TAKES place at the face AC, the angle of incidence at the face AC, `i gt theta_C`, `60^@ gttheta_Corsin 60 ^@gt ( 2mu )/(3 )or mu lt (3 sqrt(3))/(4)` |
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| 38536. |
The magnetic moment per unit volume of the material is termed as ............... . |
| Answer» SOLUTION :INTENSITY of MAGNETISATION | |
| 38537. |
In a closed flask of 5 litre, 1.0 g of H_(2) is heated from 300-600K. Which statement is not correct? |
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Answer» The rate of COLLISION increases |
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| 38538. |
The power of a lens is +2D. a . What do you mean by this ? b How is power related to its focal length ? |
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Answer» <P> Solution :a. Power P = + 2D `therefore 2 = (1)/(f_((m)) ) ,"" therefore f_((m)) = (1)/(2) = 0.5 ` mit MEANS power of a LENS is + 2 dioptres and the lens is convex lens. b. Power = `(1)/("FOCAL length (in metre)")` `P = (1)/(f_((m))) ` |
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| 38539. |
The ratio of longest wavelength and the shortest wavelength as observed in the five spectral series of emission spectrum of hydrogen is: |
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Answer» `4/3` `1/lambda =R [1/1^(2)-1/n^(2)]` `lambda " SHORTEST" =1/R" as n="oo` For Pfund SEREIS `1/lambda =R[1/5^(2)-1/n^(2)]` `((1)/(lambda_("longest")))=R/(25)-(R)/(36)` As n=6 `(lambda_("longest"))/(lambda_("shortest"))=(25 xx 36)/(11R) xx R=(900)/(11)` |
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| 38540. |
To transmit signals in the range 30-300 MHz space Sr wave propagation is used. What is meant by space wave propagation? |
| Answer» Solution :In space wave PROPAGATION, wave TRAVELS in STRAIGHT LINE from transmitting ANTENNA to the receiving antenna. | |
| 38541. |
Huygen's principle of secondary wavelets can be used to |
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Answer» IND out SPEED of LIGHT in a medium |
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| 38542. |
The north of a bar magnet is moved towards a coil along the axis passing through the centre of the coil and perpendicular to the plane of the coil. The direction of the induced current in the coil when viewed in the direction of the motion of the magnet is |
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Answer» CLOCKWISE |
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| 38543. |
Resources which are found in a region but have not been utilised are called: |
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Answer» DEVELOPED resources |
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| 38544. |
A ray of light from air is incident on a sphere of refractive index sqrt(3). If the angle of incidence is 60^(@) , calculate the angle between the incident ray and the emergent ray with the help of a diagram. |
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Answer» |
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| 38545. |
Mentionthe principle behind the workingof a transformer. Can a transformer be used to step up a de voltage ? |
| Answer» Solution :A TRANSFORMER is based on the PRINCIPLE of mutualinduction. An emf is induced in a coil, when a changing current FLOWS through a nearby coil. It cannot be USED to step up dc voltage because induced emf cannot be PRODUCED across the secondary coil. | |
| 38546. |
Is it possible that there is a change in temperature of a body without giving/taking heat to/from it ? |
| Answer» Solution :Yes, in CASE of ADIABATIC CHANGE no heat is given or taken from the system but the temperature CHANGES. | |
| 38547. |
A cell of internal resistance 5.1 Omega and of e.m.f. 1.5 volt balances 500 cm on a potentiometer wire. If a wire of 15Omega is connected between the balance point and the cell, then the balance point will shift |
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Answer» To ZERI |
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| 38548. |
In Young's double slit experiment with slit separation d, a monochromatic light of wavelength lamda is used. The angular separation of the fringes is |
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Answer» a. `d/(LAMDA)` |
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| 38549. |
You are to conduct a series of trials. For each trial the inclination of the plane is set to an angle theta, ranging from 0^(@)to 90^(@) and an object is released from rest at the top of the stationary inclined plane. The coefficient of static friction between the object and the inclined plane is mu_(s). In each case below, predict the observed outcome for the trial. In the following equation 'tumble' means 'tip' over and rotate' and 'sliding' means NO tumblingCase2 : The object is a cube and mu_(s)=0 In this experiment, the angle theta is varied only between 0^(@) and 45^(@) |
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Answer» The cube will slide down for all `45^(@)gtthetagt0^(@)` |
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| 38550. |
You are to conduct a series of trials. For each trial the inclination of the plane is set to an angle theta, ranging from 0^(@)to 90^(@) and an object is released from rest at the top of the stationary inclined plane. The coefficient of static friction between the object and the inclined plane is mu_(s). In each case below, predict the observed outcome for the trial. In the following equation 'tumble' means 'tip' over and rotate' and 'sliding' means NO tumblingCase3 : The object is a cube and mu_(s) is very large (mu gt gt 1) |
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Answer» the cube will remain at REST for SMALL theta and slide down only for theta greater than a certain non-zero value |
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