Can you please give me the Central University PhD entrance exam past year question papers as it is very urgent for me?

As you want to get the Central University PhD entrance exam past year question papers so here is the information of the same for you:

1. The coefficient of viscosity has the following dimensions :

(A) [M L-1 T-1] (B) [ML2 T-3]

(C) [M L-1 T-2] (D) [ M L2 T4]

2. The number of significant figures in 0.00150 is :

(A) 2 (B) 3

(C) 4 (D) 5

3. The velocity of an object is given as a function of time by v = 4t – 3t2, where v is in m/s and t in seconds. Its average velocity over the interval from t = 0 to t = 2 seconds is :

(A) 0 (B) –2 m/s

(C) 2 m/s (D) –4 m/s

4. We send a beam of light, travelling at the speed of light c, toward a distant galaxy, which is receding from us with a speed of 0.90 c. Observers in the galaxy see the light coming toward them with a speed of ?

(A) 0 (B) 0.10 c

(C) c (D) 1.9 c

5. A particle is executing circular motion. At any moment the position of the particle is (i j) ^ ^ + cm. The velocity of the particle at this moment will be along the direction :

(A) ^i (B) ^j

(C) (i j) ^ ^ + (D) (i – j) ^ ^

6. A ball is thrown downward from the edge of a cliff with an initial speed that is greater than the terminal speed. Initially its acceleration is :

(A) 0 (B) upward

(C) downward and greater than g (D) downward and less than g

7. A particle moves 5m in the +x direction while being acted upon by a constant force F (4 i 2 j 4k) N ^ ^ ^ = + − → The work (in Joules) done on the particle by this force is :

(A) 20J (B) 10J

(C) –20J (D) 30J

8. A block slides across a rough horizontal table top. The work done by friction changes :

(A) only the kinetic energy (B) only the potential energy

(C) only the kinetic and potential energy (D) only the kinetic and internal energy

9. A 75 kg man is riding in a 30 kg cart at 2.0 m/s. He jumps off in such a way as to land on the ground with no horizontal velocity. The resulting change in speed of the cart is :

(A) 0 (B) 2.0 m/s

(C) 3.0 m/s (D) 5.0 m/s

10. The angular momentum vector of the Earth about its rotation axis, due to its daily rotation, is directed :

(A) tangent to the equator toward the east (B) tangent to the equator toward the west

(C) due north (D) due south

11. A 2.0 kg block starts from rest on the positive x axis 3.0m from the origin and thereafter has

acceleration given by, a = 4.0 ^i – 3.0 ^j in m/s. The torque, relative to the origin, acting on it at the end of 2.0 s is :

(A) 0 (B) (- 12 N.m) ^k

(C) (+ 24 N.m) ^k (D) (-144 N.m) ^k

12. An ice skater with rotational inertia Io is spinning with angular speed o ω . She pulls her arms in, decreasing her rotational intertia to Io/3. Her angular speed becomes :

(A) 3 o ω (B) o ω

(C) / 3 o ω (D) o ω /3

13. A certain wire stretches 1cm. when a force F is applied on it. The same force is applied to a wire of the same material but with twice the diameter and twice the length. The second wire stretches :

(A) 0.25 cm (B) 0.5 cm

(C) 1 cm (D) 2 cm

14. Two particles, each of mass m, are a distance d apart. To bring a third particle, also with mass m, from far away to the point midway between the two particles an external agent does work given by :

(A) 4G m2 /d (B) –4G m2 /d

(C) 4Gm2 /d2 (D) –4Gm2 /d2

15. A student standardizes the concentration of a salt water solution by slowly adding salt until an egg will just float. The procedure is based on the assumption that :

(A) all eggs have the same volume (B) all eggs have the same weight

(C) all eggs have the same density (D) all eggs have the same shape.

16. A constriction in a pipe reduces its diameter from 4.0 cm to 2.0 cm. Where the pipe is wide the water velocity is 8.0 m/s. Where it is narrow the water velocity is :

(A) 4.0 m/s (B) 8.0 m/s

(C) 16.0 m/s (D) 32.0 m/s

17. A particle moves in simple harmonic motion according to x = 2 cos (50 t), where x is in meters and t in seconds. Its maximum velocity in m/s is :

(A) 100 sin (50t) (B) 100 cos (50t)

(C) 100 (D) 200

18. A string carries a sinusoidal wave with an amplitude of 2.0 cm. and frequency of 100Hz. The maximum speed of any point on the string is :

(A) 13.0 m/s (B) 1.30 m/s

(C) 0.13 m/s (D) 6.3 m/s

19. A source S generates circular outgoing waves on a lake. The wave speed is 5.0m/s and the crest-to crest distance is 2.0m. A person in a motor boat heads directly toward S at 3.0 m/s to this person, the frequency of these waves is :

(A) 1.0 Hz (B) 1.5Hz

(C) 2.0Hz (D) 4.0Hz

20. When work W is done on an ideal gas of diatomic molecules in thermal isolation the increase in the total translational kinetic energy of the molecules is :

(A) W (B) 3W/5

(C) 2W/5 (D) 2W/3

21. An ideal gas of N diatomic molecules has temperature T. If the number of molecules is doubled without changing the temperature, the internal energy increases by :

(A) 1/2NkT (B) 3/2NkT

(C) 5/2NkT (D) 0

22. Which of the following process leads to no change in entropy ?

(A) Non–cyclic isobaric (B) Non–cyclic isochoric

(C) Non-cyclic isothermal (D) Any closed cycle

23. In a thermally insulated kitchen, an ordinary refrigerator is turned on and its door is left open. The temperature of the room :

(A) remains constant by first law of thermodynamics

(B) increases by first law of thermodynamics

(C) decreases by first law of thermodynamics

(D) remains constant by second law of thermodynamics

24. A perfectly reversible heat pump supplies heat to a building to maintain its temperature at 27o C. The cold reservoir is a river at 7o C. If work is supplied to the pump at the rate of 1k W, at what rate does the pump supply heat to the building :

(A) 15 kW (B) 3.85 kW

(C) 1.35 kW (D) 30.0 kW

25. If wavelengths of maximum intensity of radiation emitted by sun and moon are 0.5 X 10–6 m and 10–4 m respectively, the ratio of their temperature is :

(A) 1/100 (B) 1/200

(C) 100 (D) 200

26. The height through which a liquid rises in a capillary depends upon :

(A) surface tension of the liquid and the radius of the capillary

(B) surface tension and density of the liquid and the radius of the capillary

(C) surface tension only

(D) surface tension and the density of the liquid.

27. A uniform U – tube is partially filled with water. Oil, of density 0.75 gm/cm3, is poured into the right arm until the water level in the left arm rises 3 cm. The length of the oil column is :

(A) 2.25 cm (B) 8 cm

(C) 10 cm (D) 4 cm

28. The coefficient of linear expansion of iron is 10–5 per 0 C. The volume of an iron cube, 5cm on edge will increase by what amount if it is heated from 10 0C to 6 oC ?

(A) 0.00375 cm3 (B) 0.1875 cm3

(C) 0.0225 cm3 (D) 0.00125 cm3

29. The excess of pressure inside a soap bubble is twice the excess pressure inside a second soap bubble. The volume of the first bubble is n times the volume of the second, where n is :

(A) 0.125 (B) 0.250

(C) 2 (D) 4

30. When a certain string is clamped at both ends, the lowest four resonant frequencies are 50, 100, 150, and 200Hz. When the string is also clamped at its mid point, the lowest four resonant frequencies are :

(A) 50,100, 150, and 200 Hz (B) 50, 150, 250, and 300 Hz

(C) 100, 200, 300, and 400 Hz (D) 25, 50, 75, and 100 Hz

31. The proton is the nucleus of the hydrogen atom, and it attracts the electron that orbits it. Relative to this force, the electron attracts the proton with :

(A) more force (B) less force

(C) same force (D) force depending on mass of proton and electron

32. Five identical point charges are placed at the corners of a regular hexagon of side L metres. Resultant force on a -q charge placed at centre of hexagon is :

(A) 0 (B) kq2/L2

(C) kq/L2 (D) 2kq2/L2

33. The capacitance of a parallel plate capacitor is 2.5 μF. When it is half filled with dielectric, its capacitance becomes 5μF. The dielectric constant of the dielectric is :

(A) 7.5 (B) 3

(C) 0.3 (D) 4

34. A human being can just feel the effect of electric current if the current is in the order of :

(A) micro ampere (B) milli ampere

(C) 1 A (D) 10 A

35. 12 wires of equal resistance R, are connected to form a cube. The effective resistance between diagonal ends will be :

(A) 5R/6 (B) 6R/5

(C) 3R (D) 12 R

36. If length, thickness, specific resistance and current flowing in the potentiometer wire is doubled, then the potential gradient will be :

(A) quadrupled (B) 8 times

(C) twice (D) unchanged

37. Two bar magnets of same mass and dimensions but having magnetic moment M and 2M are joined together pole to pole and suspended by a string. The time period of assembly in a magnetic field H is 3s. If now the polarity of one of the magnets is reversed and the combination is again made to oscillate in the same field, the time of oscillation is :

(A) √3s (B) 3√3s

(C) 3s (D) 6s

38. The magnetic moment of the magnet of mass 75g is 9 × 10-7 Am2. If the density of magnetic material is 7500kg/m3, then intensity of magnetisation is :

(A) 0.9A/m (B) 0.09A/m

(C) 9A/m (D) 90A/m

39. Electric power is generally transmitted over long distances at high voltage AC. The reason is :

(A) the high voltage on transmission line prevents theft of line wire

(B) power can be transmitted more quickly

(C) there is less wastage of power in transmission at high voltages

(D) large amounts of power cannot be generated at low voltages

40. An electric generator is based on the principle of :

(A) Ohm’s law

(B) variation in magnetic flux due to rotation of armature coil in the region of magnetic field

(C) variation of electric flux across the armature coil

(D) chemical energy conversion to electrical energy

41. The current flowing through the inductance coil of resistance 173 ohm which is connected to 50 Hz A.C. is found to lag the supply voltage by an angle of 30o. The inductance of the coil is about :

(A) 0.4H (B) 0.2H

(C) 0.3H (D) 0.1H

42. Radio wave is :

(A) long wavelength light wave (B) highly penetrative light wave

(C) Sound wave (D) low wavelength light wave

43. In Young’s experiment the wavelength of blue and red lights are 78μm and 52μm respectively. The value of n for which (n+1)th blue bright band coincides with nth red bright band is :

(A) 4 (B) 3

(C) 2 (D) 1

44. A diffraction pattern is observed using red light. What happens if the red light is replaced by the blue light ?

(A) no change (B) diffraction bands become narrower

(C) bands become broader (D) bands disappear

45. In LCR circuit, the sharpness of the resonance curve :

(A) decreases with increase of inductance L (B) decreases with increase of capacitance C

(C) doesn’t depend upon value of L, C, R (D) decreases with increase of resistance R

46. The focal length of a convex lens of glass of refractive index 1.50 is 2cm. The focal length of this lens when it is immersed in a liquid of refractive index 1.25 will be :

(A) 1 cm (B) 2.5 cm

(C) 4 cm (D) 5 cm

47. As the quantum numbers increase, the difference in consecutive energy levels of the hydrogen atom :

(A) remains same (B) decreases

(C) increases (D) can not be predicted

48. When the 88Ra236 decays in a series by emission of 3α particles and a β particle, the daughter nucleus formed will be :

(A) 83Bi224 (B) 84Po224

(C) 85At220 (D) 87Fr223

49. If a sample of radioactive isotope has a half-life of 1 day, how much of the original sample will remain at the end of third day ?

(A) 1/2 of original sample (B) 3/4 of original sample

(C) 1/3 of original sample (D) 1/8 of original sample

50. Energy generation in stars is mainly due to :

(A) fission of heavy nuclei (B) fission of light nuclei

(C) fusion of light nuclei (D) fusion of heavy nuclei

51. On increasing the reverse bias voltage to a large value in a pn junction diode the current :

(A) increases slowly (B) remains constant

(C) suddenly increases (D) decreases slowly

52. Which of the following is the ideal diode I-V Characteristic curve ?

Diagram.

53. The three primary colours are :

(A) red, blue and green (B) red, orange and blue

(C) red, green and yellow (D) red, yellow and blue

54. From which layer of atmosphere, radio waves are reflected back ?

(A) troposphere (B) mesosphere

(C) stratosphere (D) ionosphere

55. The velocity of electromagnetic wave in free space is :

(A) √(μ0/ 0 ε ) (B) √(μ0 0 ε )

(C) √(1/ μ0 0 ε )) (D) √( 0 ε /μ0)

56. How many frequencies are there in the visible part of electromagnetic spectrum ?

(A) three (B) seven

(C) zero (D) infinite number

57. Boolean expression for NAND gate is :

(A) A = –A (B) A + B +C = y

(C) AB = y (D) A + B = y

58. Electric conduction in a semiconductor takes place due to :

(A) electrons only (B) holes only

(C) electrons and holes (D) neither electrons nor holes

59. When an impurity is doped into an intrinsic semiconductor, the conductivity of the semiconductor :

(A) increases (B) decreases

(C) becomes zero (D) remains same

60. A logical circuit can be constructed by using only :

(A) AND gates (B) OR gates

(C) NOR gates (D) NOT gates

ANSWERS/KEY

Subject: Physics

1 2 3 4 5 6 7 8 9 10

A B A C D B A D D C

11 12 13 14 15 16 17 18 19 20

X A B B C D C A D B

21 22 23 24 25 26 27 28 29 30

C D B A X B B X A C

31 32 33 34 35 36 37 38 39 40

C B B B A D B B C B

41 42 43 44 45 46 47 48 49 50

C A X B D D B A D C

51 52 53 54 55 56 57 58 59 60

C A A D C D C C A C

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Central University of Rajasthan

Kishangarh,

Rajasthan

01463 238 755

India

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