physics mcq pdf

8/11/2019 Physics MCQ PDF

http://slidepdf.com/reader/full/physics-mcq-pdf 1/13

Check more Papers onwww.exams.qoney.com

1. The frequency of vibration of string is given by

Here p is number of segments in the string and 1 is the length. The dimensional formula for

will be(a) [M0LT-1](b) [ML0T-1](c) [ML-1T0](d) [M0L0T0]Ans. (c)

2. A body of mass m rests on horizontal surface. The coefficient of friction between the body andthe surface is ii. If the mass is pulled by a force P as shown in the figure, the limiting frictiobetween body and surface will be:

(a) µmg(b) µ [mg + (p/2)](c) µ [mg - (p/2)](d) µ [mg - (√3p/2)]Ans. (c)

3. The coefficient of thermal conductivity of copper is nine times that of steel. In the compo

cylindrical bar shown in the figure, what will be the temperature at the junction of copper asteel?

(a) 25°C(b) 33°C(c) 67°C(d) 75°CAns. (d)

4. A galvanometer gives full scale deflection with 0.2 A in a coil as shown in the figure. Thresistance of its coil is 10Ω. How much shunt resistance is required to convert it into an ammeto read current upto 1.8 A?




(a) 1.25Ω (b) 2.5Ω (c) 5.0Ω (d) 10.0Ω Ans. (a)

5. In the Boolean algebra is same as

(b)A.B

(d)A + BAns. (a)

6. A hypothetical experiment conducted to determineYoung’s formula

If Y = Young’s modulus, T = time period,τ= torque and I = length, then find the value of(a) Zero(b) 1(c) 2(d) 3Ans. (a)

7. A particle of mass m, strikes on ground with angle of incidence 45°. If coefficient ofRestitution e = 1/ √2, the velocity of reflection Is(a)√3/2 v(b)√3v(c) v/2(d) v/ √3Ans. (a)

8 Two blocks, one of mass A =1 kg and another B = 2kg. Are shown in figure. A force of 5applied on A. Coefficient of friction between A and B is 0.2 and that between B and horizosurface is zero. Find the time taken for the front face of A to coincide with that of B.




(a) 2√2s

(d) 2sAns. (b)

9. Electric field at x =10 cm is 100 V/m and at x = -10 cm is -100 V/m. The magnitude of chargeenclosed by the cube of side 20 m is

(a) 8ε0(c) 2ε0 (b) 3ε0 (d) 5ε0Ans. (a)

10. The period of a body under SHM is represented by Tα Pa Db Sc where P is pressure, D is

density and S is surface tension. The values of a, b and c is:(a) -3 / 2 , ½, 1(b) -1,-2, 3(c) ½, -3 / 2 , -½(d) 1, 2, Ans. (a)

11. If , such that A-B = C, then ang1e between is:(a) 00 (b) 450

(c) 900

(d) 1800Ans. (d)

12. A body is projected at time (t = 0) from a certain point on a planet’s surface with a certavelocity at a certain angle with the planet’s surface. The horizontal and vertical displacemenand y (in metres) respectively vary with time t in seconds as




x = 10√3t, y = 10t -t2 Then the maximum height attained by the body is:(a) l00 m(b) 75 m(c) 50 m

(d) 25mAns. (c)

13. Two balls of masses M = 9g and m = 3g are attached by threads AO and OB, respectivelywhose combined length isl = 1 m, to a vertical axis at 0, as shown in figure and set in rotationamotion in a horizontal plane about this axis with a constant angular velocity w. The ratio oflengths AO and OB for which the tensions in the threads will be same : (Neglect the weightthreads)

(a) 1 : 1(b) 1 : 2(c) 1 : 3(d) 2 : 3Ans. (c)

14. A solid disc rolls clockwise without slipping over horizontal path with constant speed vThen magnitude of velocity at A, B and C with respect to observer on ground is:

(a) v, v and v(b) 2v, 2v and 2v(c) 2v,√v and zero(d) 2v, v and zeroAns. (c)

15. A particle is moving along a circular path with an angular speed o about the axis passinthrough the centre. What will be its angular speed about a point on the other end of the diamthrough, the instantaneous position of the particle?(a)∞ / 4(b)∞ / 2(c)∞




(d) 2∞ Ans. (b)

16.Two particles of masses m and M are initially at rest and infinitely separated from each oDue to mutual interaction they approach each other. Their relative velocity of approach at a

separation of distance d between them, is:

Ans. (b)

17. A string of length L and mass M hangs freely from a fixed point. Then thevelocity oftransverse waves along the string at a distance x from the free end is:(a)√gL

(b)√gx(c) gL

(d) gxAns. (b)

18. A charge +q is carried from a point A (r, 135°) to point B (r, 450) following a path whicquadrant of circle of radius r. If the electric dipole moment is p. the work done by the externagent is:

Ans. (c)

19. A thin metal plate p is inserted between the plates of a parallel plate capacitor of capacitC in such a way that its edge touch the two plates forming Z shape as shown in figure. Thecapacitance now becomes:

(a)C / 2(b) 2C




(c) zero(d) infiniteAns. (d)

20. A flash light lamp is marked 3.5 V, 0.28 A. The filament temperature is 425°C. The fila

resistance when cold is 4Ω

. The temperature coefficient of material of the filament is(a) 8.5 x 10-2/ K(b) 2.5 x 10-3 /K(c) 4.25 x 10-4 /K(d) 5.0 x 10-3 /KAns. (d)

21. A resistor R = 9Ω is connected across a source of emf as shown in the figure (a). Its emfchanges with time as shown in the graph figure (b). What is the heat developed in the resistfor the first 6 s?

(a) 64J(b) 96J(c) 108J(d) 128JAns. (d)

22. ABED is a square loop made of a uniform conducting wire. A current enters the loop atand leaves at D. The magnetic field is:

(a) zero at all points inside the loop(b) zero at all points outside the loop(c) maximum at the centre of the loop(d) zero only at the centre of the loopAns. (d)Ans. (c)

23. A conducting wire is stretched between the poles of a magnet. There is a strong uniformmagnetic field in the region between the poles. If an AC current I = I sin to is passed througwire AB, then the wire will




(a) remain stationary(b) be pulled towards N-pole(c) be pulled towards S-pole(d) vibrate with frequencyAns. (d)

24. A92U235 reactor takes 30 days to use up 2 kg of fuel and each fission gives185 MeV ofusable energy. The number of moles used up in 30 days is:(a) 2 x 103 /235

(b) 235

(c) 2(d) 2 x 235Ans. (a)

25. Two identical capacitors each of capacitance C are charged to the same-potential wand connected in two circuits (a) and (b) att = 0 as shown. The charges on the capacitors at t = Care:

(a) CV, CVe e

(b) CV, CV(c) VC, VC

e(d) VC, VC

eAns. (c)

26. The combination of the gates shown below produces




(a) AND gate(b) XOR gate(c) NOR gate(d) NAND gateAns. (d)

27. A 50 kg girl is swinging on a swing from rest, then the power delivered whenmoving with avelocity of 2 m/s upwards in a direction making an angle of 60° with the vertical is:(a) 980 W(b) 490 W(c) 490√3 W(d) 245 WAns. (c)28. A ball of mass m is suspended from a thread of length 1. The ball is moved up from theposition of equilibrium to the suspension height and then released. At what value of angle aangle between the thread and the vertical) will the thread be broken if it can withstand tensiequal to twice the weight of the ball?

Ans. (b)

29. A tunnel is dug along a diameter of the earth (mass Me and radius Re). The force on aparticle of mass m placed in the tunnel at a distance r from the centre is:

Ans. (a)




30. The value of X which gives zero deflection in the galvanometer shown in figure is:

(a) 3Ω (C) 18Ω (b) 6Ω (d) 15Ω Ans. (c)

31. In the circuit given, the heat produced per second between pointsX and Y is:

(a) 480 J/s(b) 240 J/s(c) zero(d) 492 J/sAns. (c)

32. Three similar bar magnets are placed to form an equilateral triangle as shown in figure. magnetic moment of each magnetism. What is the magnetic moment of the system?

(a) zero

(b) M/2(c) M(d) 2MAns. (d)

33. The Kα X-rays emission line of tungston occurs atλ = 0.021 nm. The energy differencebetween K and L levels in this atom is about:




(a) 0.51 MeV(b) 1.2 MeV(c) 59 keV(d) 13.6 eVAns. (c)

34. In the Boolean algebra is same as

(b)A.B

(d)A + BAns. (a)

35. A hypothetical experiment conducted to determine Young’s formula

If Y = Young’s modulus, T = time period,τ= torque and I = length, then find the value of(a) Zero(b) 1(c) 2(d) 3Ans. (a)

36. A particle of mass m, strikes on ground with angle of incidence 45°. If coefficient ofRestitution e = 1/ √2, the velocity of reflection Is(a)√3/2 v

(b)√3v(c) v/2

(d) v/ √3Ans. (a)

37 Two blocks, one of mass A =1 kg and another B = 2kg. Are shown in figure. A force of applied on A. Coefficient of friction between A and B is 0.2 and that between B and horizosurface is zero. Find the time taken for the front face of A to coincide with that of B.

(a) 2√2s

(d) 2s




Ans. (b)

38. Electric field at x =10 cm is 100 V/m and at x = -10 cm is -100 V/m. The magnitude of

charge enclosed by the cube of side 20 m is

(a) 8ε0(c) 2ε0 (b) 3ε0 (d) 5ε0Ans. (a)

39. A body of mass 2 kg has an initial velocityof 3 m/s along OE and it is subjected to a force of4 N in a direction perpendicular to OE. The distance of body from 0 after 4s will be:

(a) 12m(b) 20m(c) 8m(d) 48mAns. (b)

40. The escape velocity of a body depends upon the mass as:

Ans. (a)

41. If R is the radius of a planet, g ‘lie the acceleration due to gravity, then the mean densitythe planet will be:




Ans. (d)

42. A thin circular ring of mass M and radius r is rotating about its axis with a constant angularvelocity w. If two objects, each of mass m are attached to the opposite ends of a diameter ofring, the ring will now rotate with an angular velocity of:

Ans. (d)

43. A body of mass 100 g is sliding on an inclined plane with inclination of 30°. The frictioforce experienced by the body, if the coefficient of friction µ is 1.7, will be

Ans. (c)

44. A force is given by, where t is time. The dimension of a and b is:

Ans. (c)

45. The moment of inertia of disc about a tangent axis in its plane is




Ans. (c)

46. The time taken by the light to cross a glass of thickness 4 mm and refractive index (µ=

Ans. (d)

47. What is the coefficient of mutual induction when the magnetic flux changes by Wband change in current is 0.01 A?(a) 8H(b) 4H(c) 3H(d) 2HAns. (d)

48. There is a solid sphere of radius R of metal having uniformly distributed charge. What irelation between electric field E and distance r from the centre (r < R)?

Ans. (b)

49. The 6563 line emitted by hydrogen atom in a star is found to be red shifted by 15 Å, thespeed with which the star is receding from the earth is:

Ans. (d)

50. Two trains traveling on the same’ tack are approaching each other will equal speeds of 4m/s. The drivers of the trains begin to decelerate simultaneously when they are just 2.0 km Assuming the deceleration to be uniform and equal. The value of deceleration to barely avocollision should be:

Ans. (a)

physics mcq pdf

Documents