UP PGT 2016 — Physics (Series A)

Physics

1. 1. Kepler’s second law – areal velocity remains constant – is equivalent to which of the following conservation laws ?

   • (a) Energy
   • (b) Linear momentum
   • (c) Angular momentum
   • (d) None of the above
   उत्तर देखें

   उत्तर: (c)

2. 2. At what temperature will the Fahrenheit and Kelvin thermometer scales give the same numerical value ?

   • (a) – 40.75°
   • (b) 180.25°
   • (c) 435.50°
   • (d) 574.25°
   उत्तर देखें

   उत्तर: (d)

3. 3. In Joule-Thompson effect, which quantity remains constant ?

   • (a) Temperature
   • (b) Enthalpy
   • (c) Entropy
   • (d) Internal energy
   उत्तर देखें

   उत्तर: (b)

4. 4. The ratio of intensities of two light waves is 25 : 16. If they interfere, the ratio of intensities of maxima and minima of resultant pattern is

   • (a) 5 : 4
   • (b) 9 : 1
   • (c) 49 : 9
   • (d) 81 : 1
   उत्तर देखें

   उत्तर: (d)

5. 5. A ray of light is incident at polarising angle on a transparent plate of refractive index √3. What is the angle of refraction ?

   • (a) 30°
   • (b) 60°
   • (c) 90°
   • (d) 120°
   उत्तर देखें

   उत्तर: (a)

6. 6. Two lenses of focal lengths f₁ and f₂ are at a distance d from each other. When will the spherical aberration be minimum ?

   • (a) d = ½(f₁ + f₂)
   • (b) d = ½(f₁ – f₂)
   • (c) d = f₁ – f₂
   • (d) d = f₁ + f₂
   उत्तर देखें

   उत्तर: (c)

7. 7. An electric charge q is placed at the centre of a cube of side l. The electric flux passing through one of its faces is

   • (a) q/(6ε₀)
   • (b) q/(lε₀)
   • (c) q/(l²ε₀)
   • (d) ql²/(4πε₀)
   उत्तर देखें

   उत्तर: (a)

8. 8. A wire of 40 Ω resistance is bent to form a complete circle as in the figure. What is the effective resistance between points A and B ?

   • (a) 40.33 Ω
   • (b) 30.66 Ω
   • (c) 7.50 Ω
   • (d) 5.00 Ω
   उत्तर देखें

   उत्तर: (c)

9. 9. The shortest wavelength in the radiation obtained from an X-ray tube having accelerating voltage of 50,000 volts is about

   • (a) 0.0025 Å
   • (b) 0.025 Å
   • (c) 0.250 Å
   • (d) 2.5 Å
   उत्तर देखें

   उत्तर: (c)

10. 10. The function of a grid in the triode is to control the

    • (a) Cathode potential
    • (b) Filament current
    • (c) Cathode temperature
    • (d) Anode current
    उत्तर देखें

    उत्तर: (d)

11. 11. The source of solar energy is

    • (a) Chemical reactions
    • (b) Nuclear fusion
    • (c) Nuclear fission
    • (d) Gravitational interaction with other solar systems
    उत्तर देखें

    उत्तर: (b)

12. 12. The maximum efficiency of a half wave rectifier can be

    • (a) 25.3%
    • (b) 40.6%
    • (c) 50.5%
    • (d) 81.2%
    उत्तर देखें

    उत्तर: (b)

13. 13. The excess pressure inside a soap bubble of radius 3 mm will be (Surface tension is 0.03 N/m)

    • (a) 60 N/m²
    • (b) 120 N/m²
    • (c) 40 N/m²
    • (d) 80 N/m²
    उत्तर देखें

    उत्तर: (c)

14. 14. Three capillaries of equal lengths but internal radii r, 2r and 3r respectively are connected in series, a liquid flows in streamline motion through them. If the pressure difference across the entire system is 77 cm (of water), then the pressure difference across the first capillary is

    • (a) 71.64 cm
    • (b) 70.32 cm
    • (c) 76.00 cm
    • (d) 77.00 cm
    उत्तर देखें

    उत्तर: (a)

15. 15. The ratio of the gram molecular specific heats (γ) of a diatomic gas is

    • (a) 1.66
    • (b) 1.33
    • (c) 1.40
    • (d) 1.00
    उत्तर देखें

    उत्तर: (c)

16. 16. If the root mean square velocity of hydrogen molecules at NTP is 1.84 km/sec, what will it be for oxygen molecules at NTP ?

    • (a) 0.42 km/sec
    • (b) 0.40 km/sec
    • (c) 0.38 km/sec
    • (d) 0.46 km/sec
    उत्तर देखें

    उत्तर: (d)

17. 17. The potential difference of an electron microscope is increased from 20 kV to 80 kV. Its resolving power will become

    • (a) Two times
    • (b) Four times
    • (c) Half
    • (d) Quarter
    उत्तर देखें

    उत्तर: (a)

18. 18. Which of the following is incorrect ?

    • (a) Zone plate has many focii
    • (b) Zone plate is similar to convex lens
    • (c) Focal length of zone plate depends on wavelength of light used
    • (d) None of the above
    उत्तर देखें

    उत्तर: (d)

19. 19. A spring has length 10 cm and a force constant 10³ N/m. Two masses of 10 gm and 90 gm are attached to its ends. The spring is placed on a horizontal table, stretched and released. What is the frequency of oscillation ?

    • (a) 50 Hz
    • (b) 45 Hz
    • (c) 53 Hz
    • (d) 60 Hz
    उत्तर देखें

    उत्तर: (c)

20. 20. What is the fundamental basis of a laser ?

    • (a) Absorption
    • (b) Spontaneous emission
    • (c) Stimulated emission
    • (d) Scattering
    उत्तर देखें

    उत्तर: (c)

21. 21. On moving from the surface towards the centre of a charged solid metal sphere, the electric field

    • (a) Increases
    • (b) Decreases
    • (c) Is same as on surface
    • (d) Is everywhere zero
    उत्तर देखें

    उत्तर: (d)

22. 22. The current flowing in a coil of self induction 0.4 mH is changed by 250 mA in 0.1 seconds. What is the induced emf in the coil ?

    • (a) – 1 mV
    • (b) – 2 mV
    • (c) – 3 mV
    • (d) – 5 mV
    उत्तर देखें

    उत्तर: (a)

23. 23. A 220 volt A.C. source is connected across an inductance of One Henry. If the frequency of the source is 50 Hz then what is the powerloss ?

    • (a) 220 W
    • (b) 110 W
    • (c) 440 W
    • (d) Zero
    उत्तर देखें

    उत्तर: (d)

24. 24. An X-ray tube operates at 20 kV. Which of the following is correct ? 1) 0.5 Å wavelength will be absent 2) 0.8 Å wavelength will be present (h = 6.6 × 10⁻³⁴ Js, c = 3 × 10⁸ m/s, 1 eV = 1.6 × 10⁻¹⁹ J)

    • (a) Only 1
    • (b) Only 2
    • (c) Both 1 and 2
    • (d) Neither 1 nor 2
    उत्तर देखें

    उत्तर: (c)

25. 25. The half life of radon is 3.8 days starting with 9.6 mg of radon, how much will be left after 19 days ?

    • (a) 0.5 mg
    • (b) 0.6 mg
    • (c) 0.3 mg
    • (d) 0.2 mg
    उत्तर देखें

    उत्तर: (c)

26. 26. Dimension of 1/(μ₀ε₀) is

    • (a) [LT⁻¹]
    • (b) [L⁻¹T]
    • (c) [L⁻²T²]
    • (d) [L²T⁻²]
    उत्तर देखें

    उत्तर: (d)

27. 27. Two lenses of powers +4D and –2D are kept in contact. The combinations focal length will be

    • (a) 100 cm
    • (b) 75 cm
    • (c) 50 cm
    • (d) 25 cm
    उत्तर देखें

    उत्तर: (c)

28. 28. Law of Malus is

    • (a) I = I₀ Sin² θ
    • (b) I = I₀ Sin θ
    • (c) I = I₀ Cos² θ
    • (d) I = I₀ Tan² θ
    उत्तर देखें

    उत्तर: (c)

29. 29. A transistor amplifier has β = 30, R_Load = 4000 Ω and input resistance R_in = 400 Ω. Its voltage amplification is

    • (a) 100
    • (b) 200
    • (c) 300
    • (d) 400
    उत्तर देखें

    उत्तर: (c)

30. 30. Formula for variation of acceleration due to gravity while going above the surface of the earth is

    • (a) g′ = g/(1 – h/Re)²
    • (b) g′ = g/(1 – h/Re)
    • (c) g′ = g/(1 + h/Re)
    • (d) g′ = g/(1 + h/Re)²
    उत्तर देखें

    उत्तर: (d)

31. 31. For a perfectly rigid body, Young’s modulus of elasticity will be

    • (a) ∞
    • (b) 100
    • (c) 1
    • (d) 0
    उत्तर देखें

    उत्तर: (a)

32. 32. What remains constant during simple harmonic motion ?

    • (a) Restoring force
    • (b) Kinetic energy
    • (c) Potential energy
    • (d) Time period
    उत्तर देखें

    उत्तर: (d)

33. 33. What is the relation between phase difference (Δϕ) and path difference (Δx) ?

    • (a) Δϕ = (2π/λ)Δx
    • (b) Δϕ = (λ/2π)Δx
    • (c) Δϕ = λ/(2πΔx)
    • (d) Δϕ = (π/λ)Δx
    उत्तर देखें

    उत्तर: (a)

34. 34. When the net external torque acting on a rigid body is zero, then what becomes constant ?

    • (a) Linear momentum
    • (b) Energy
    • (c) Angular momentum
    • (d) None of the above
    उत्तर देखें

    उत्तर: (c)

35. 35. Two capillaries of diameter 5 mm and 4 mm respectively are standing in water. The water rises 5.7 mm in the first one (diameter 5 mm). How much will it rise in the other capillary ?

    • (a) 5.7 mm
    • (b) 7.1 mm
    • (c) 6.6 mm
    • (d) 9.9 mm
    उत्तर देखें

    उत्तर: (b)

36. 36. What does diffraction indicate ?

    • (a) Particle nature
    • (b) Wave nature
    • (c) Both particle and wave nature
    • (d) None of the above
    उत्तर देखें

    उत्तर: (b)

37. 37. The graph between square of time period and length of a simple pendulum is

    • (a) Straight line
    • (b) Circle
    • (c) Parabola
    • (d) Hyperbola
    उत्तर देखें

    उत्तर: (a)

38. 38. Sound waves in hydrogen gas are of which type ?

    • (a) Transverse
    • (b) Longitudinal
    • (c) Stationary
    • (d) Electromagnetic
    उत्तर देखें

    उत्तर: (b)

39. 39. In an AC circuit resonance condition is

    • (a) L > 1/(ω²C)
    • (b) L < 1/(ω²C)
    • (c) L = 1/(ω²C)
    • (d) L = C
    उत्तर देखें

    उत्तर: (c)

40. 40. The internal resistance of an ideal voltmeter should be

    • (a) Zero
    • (b) Infinite
    • (c) Equal to internal resistance of source
    • (d) Negative
    उत्तर देखें

    उत्तर: (b)

41. 41. A lens of refractive index μ₂ is immersed in a medium of refractive index μ₁. The radii of curvature of the surfaces of the lense are R₁ and R₂. The focal length (f) will be

    • (a) 1/f = (μ₂ – 1)(1/R₁ – 1/R₂)
    • (b) 1/f = (μ₂/μ₁ – 1)(1/R₁ – 1/R₂)
    • (c) 1/f = (μ₂/μ₁ – 1)(1/R₁ + 1/R₂)
    • (d) 1/f = (μ₁/μ₂ – 1)(1/R₁ + 1/R₂)
    उत्तर देखें

    उत्तर: (b)

42. 42. If the phase difference between an alternating current and voltage is π/2, which of the following can not be part of the circuit ?

    • (a) R, L both present
    • (b) C alone present
    • (c) L alone present
    • (d) L and C both present
    उत्तर देखें

    उत्तर: (a)

43. 43. In photoelectric effect, the most energetic electrons are emitted from

    • (a) Inner shells
    • (b) Surface of metal
    • (c) Nucleus
    • (d) Deep inside the metal
    उत्तर देखें

    उत्तर: (b)

44. 44. Which of the following is the unit of strain ?

    • (a) Joule
    • (b) Newton
    • (c) No unit
    • (d) Watt
    उत्तर देखें

    उत्तर: (c)

45. 45. Formula Volt × Charge/Time (V × Q/T) can be equivalent to

    • (a) Acceleration
    • (b) Work done
    • (c) Power
    • (d) Velocity
    उत्तर देखें

    उत्तर: (c)

46. 46. Material having low retentivity is suitable for making

    • (a) Weak magnets
    • (b) Temporary magnets
    • (c) Permanent magnets
    • (d) Electro magnets
    उत्तर देखें

    उत्तर: —

47. 47. Which expression is incorrect ? (symbols have their usual meaning)

    • (a)
    • (b)
    • (c)
    • (d)
    उत्तर देखें

    उत्तर: (c)

48. 48. If a point charge 1.5 × 10⁻⁶ C is placed at the origin, then the 30 V equipotential surface will have radius

    • (a) 135 m
    • (b) 450 m
    • (c) 270 m
    • (d) 900 m
    उत्तर देखें

    उत्तर: (b)

49. 49. Attraction between nucleons is due to exchange of

    • (a) Photons
    • (b) Mesons
    • (c) Hadrons
    • (d) Neutrinos
    उत्तर देखें

    उत्तर: (b)

50. 50. A body of mass 2 gm and charge + 5 μC is suspended from the ceiling at the end of a string. If a horizontal electric field of 10 KV/m is applied, what is the angle between the string and vertical direction ?

    • (a) tan⁻¹ (2.55)
    • (b) tan⁻¹ (3.00)
    • (c) tan⁻¹ (3.55)
    • (d) tan⁻¹ (4.00)
    उत्तर देखें

    उत्तर: (a)

51. 51. If unpolarized light of intensity I₀ falls on a polarizer and the angle between polarizer and analyzer is 60°, then the intensity of the emergent light is

    • (a) I₀/8
    • (b) I₀/4
    • (c) I₀/2
    • (d) I₀
    उत्तर देखें

    उत्तर: (a)

52. 52. The average energy of the Planck oscillator is

    • (a) kT
    • (b)
    • (c)
    • (d)
    उत्तर देखें

    उत्तर: (b)

53. 53. When tension in a wire is T₁ its length is L₁ and when tension is T₂, its length is L₂. What is the length when there is no tension ?

    • (a) (T₂L₁ – T₁L₂)/(T₂ – T₁)
    • (b) (T₂ – T₁)/(T₂L₁ – T₁L₂)
    • (c) Zero
    • (d) (T₂L₁ – T₁L₂)/(T₂² – T₁²)
    उत्तर देखें

    उत्तर: (a)

54. 54. The gravitational field due to a mass distribution is kx^(−3/2) in X-direction at distance x (constant k > 0). If potential at infinity is zero, the potential at distance x will be

    • (a) 2k√x
    • (b) 2k/√x
    • (c) 2kx³
    • (d) 2k/x³
    उत्तर देखें

    उत्तर: (b)

55. 55. A 1m long resonance tube (internal radius 1 cm) gives first resonance at length 4.6 cm and second resonance at 14.0 cm. When a tuning fork of frequency 2000 Hz is used. What is the speed of sound ?

    • (a) 332 m/s
    • (b) 336 m/s
    • (c) 340 m/s
    • (d) 376 m/s
    उत्तर देखें

    उत्तर: (d)

56. 56. The distance x travelled by an object in time t is given by x = a + bt²/a. The dimensions of a and b are

    • (a) L, L²T⁻²
    • (b) LT⁻¹, LT⁻²
    • (c) L, LT⁻²
    • (d) L², L²T⁻²
    उत्तर देखें

    उत्तर: (a)

57. 57. If the position of a particle y is given by y = 3t³ + t² + 5, then what is the acceleration at t = 2 ?

    • (a) 5.39
    • (b) 5.38
    • (c) 37
    • (d) 38
    उत्तर देखें

    उत्तर: (d)

58. 58. If potential is given by V = 5(x² + xy), what will be the electric field at point (1, –2, 0) ?

    • (a) E⃗ = –5ĵ
    • (b) E⃗ = –5î
    • (c) E⃗ = –5î + 5ĵ
    • (d) E⃗ = –3î – 3ĵ
    उत्तर देखें

    उत्तर: (a)

59. 59. If eλ and aλ are the emissive and absorptive powers of a body and Eλ the emissive power of an ideal black body, then according to Kirchhoff’s law which relation is correct ?

    • (a) eλ = aλ = Eλ
    • (b) eλ Eλ = aλ
    • (c) eλ = aλEλ
    • (d) eλaλEλ = constant
    उत्तर देखें

    उत्तर: (c)

60. 60. A force F⃗ = 4î + 5ĵ + 6k̂ is applied on a body and it is displaced by x⃗ = 3î + 7ĵ + 8k̂. How much work is done ?

    • (a) 48
    • (b) 60
    • (c) 95
    • (d) 120
    उत्तर देखें

    उत्तर: (c)

61. 61. A ring, a circular plate, a spherical shell and a solid sphere have same mass and radius. Which will have least moment of inertia about its geometrical axis ?

    • (a) Ring
    • (b) Circular plate
    • (c) Spherical shell
    • (d) Solid sphere
    उत्तर देखें

    उत्तर: (d)

62. 62. Which one of the following represents the correct relation between various elastic constants of a material ?

    • (a) 3/Y = 9/η + 1/K
    • (b) 3/Y = 1/η + 9/K
    • (c) 9/Y = 3/η + 1/K
    • (d) 9/Y = 1/η + 3/K
    उत्तर देखें

    उत्तर: (c)

63. 63. A particle moves in a circular path with uniform speed. The direction of acceleration of the particle will be

    • (a) Along the radius
    • (b) Along the tangent to the path
    • (c) Normal to the plane of the path
    • (d) Acceleration is zero
    उत्तर देखें

    उत्तर: (a)

64. 64. Normal atmospheric pressure is 10⁵ Pascal. What force does the atmosphere exert on an area of 3 sq. cm. of your head ?

    • (a) 10 N
    • (b) 15 N
    • (c) 20 N
    • (d) 30 N
    उत्तर देखें

    उत्तर: (d)

65. 65. The first law of thermodynamics is equivalent to the conservation law of

    • (a) Temperature
    • (b) Energy
    • (c) Heat
    • (d) Momentum
    उत्तर देखें

    उत्तर: (b)

66. 66. If Cₚ and Cᵥ are the molar heat capacities of an ideal gas at constant pressure and constant volume respectively, then which of the following quantities will be a universal constant ?

    • (a) Cₚ – Cᵥ
    • (b) Cₚ + Cᵥ
    • (c) Cₚ/Cᵥ
    • (d) Cₚ.Cᵥ
    उत्तर देखें

    उत्तर: (a)

67. 67. Using light of wavelength 6000 Å in Young’s experiment, 64 fringes were observed in the field of view. How many fringes will be observed if light of wavelength 4800 Å is used ?

    • (a) 50
    • (b) 64
    • (c) 80
    • (d) 120
    उत्तर देखें

    उत्तर: (c)

68. 68. If in one complete rotation of the Nicol Prism, no variation in intensity is observed for the transmitted light, then the incident light must be which one of the following ?

    • (a) Plane polarized
    • (b) Circularly polarized
    • (c) Elliptically polarized
    • (d) Mixture of plane polarized and unpolarized
    उत्तर देखें

    उत्तर: (b)

69. 69. The equation of a damped harmonic oscillator is When will there be overdamping ?

    • (a) k < ω₀
    • (b) k = ω₀
    • (c) k > ω₀
    • (d) k = ω₀²
    उत्तर देखें

    उत्तर: (c)

70. 70. An air core solenoid has 2000 turns in a length of 60 cm. Its diameter is 2 cm. If a current of 5 amps flows through the coil, what will be the flux density within it ?

    • (a) 0.042 T
    • (b) 0.035 T
    • (c) 0.030 T
    • (d) 0.021 T
    उत्तर देखें

    उत्तर: (d)

71. 71. If the electron in the hydrogen atom jumps from the third to the second orbit, what is the wavelength of the emitted radiation ? (R ≡ Rydberg Constant)

    • (a) 36/(5R)
    • (b) 5R/36
    • (c) 5/R
    • (d) R/6
    उत्तर देखें

    उत्तर: (a)

72. 72. The equation ∇⃗ × E⃗ = –∂B⃗/∂t is the differential form of which law ?

    • (a) Ampere’s law
    • (b) Faraday law
    • (c) Coulomb law
    • (d) Gauss law
    उत्तर देखें

    उत्तर: (b)

73. 73. What potential must be applied to stop the fastest photoelectrons emitted when ultraviolet light of 2000 Å wavelength falls on a nickel surface ? (Work function of nickel = 5.01 eV)

    • (a) 5.01 V
    • (b) 3.02 V
    • (c) 2.10 V
    • (d) 1.20 V
    उत्तर देखें

    उत्तर: (d)

74. 74. Nuclear forces are

    • (a) Always repulsive
    • (b) Always attractive
    • (c) Attractive at large distances and repulsive at short distances
    • (d) Repulsive at large distances and attractive at short distances
    उत्तर देखें

    उत्तर: (c)

75. 75. What is the dimension of the coefficient of viscosity ‘η’ ?

    • (a) ML⁻¹T⁻¹
    • (b) ML⁻¹T⁻²
    • (c) ML⁻²T⁻²
    • (d) ML⁻²T⁻¹
    उत्तर देखें

    उत्तर: (a)

76. 76. If the work done by a force in moving a particle from point A to point B does not depend on the path, then the force is of which type ?

    • (a) Central
    • (b) Non-conservative
    • (c) Conservative
    • (d) Inverse square law force
    उत्तर देखें

    उत्तर: (c)

77. 77. The first law of thermodynamics for an adiabatic process is

    • (a) dU = δW
    • (b) dU = 0
    • (c) dU = – δW
    • (d) dU = –δQ + 2δW
    उत्तर देखें

    उत्तर: (c)

78. 78. A Carnot engine has the same efficiency when it works between a source at 1000° K and a sink at 500° K, as it has when the source is at T°K and sink is at 1000° K. What is the value of T ?

    • (a) 1500° K
    • (b) 2000° K
    • (c) 3000° K
    • (d) 500° K
    उत्तर देखें

    उत्तर: (b)

79. 79. A man can not see objects more distant than 40 cm. What is the power of the lens needed to allow him to see very distant objects ?

    • (a) – 3.5 D
    • (b) + 3.5 D
    • (c) – 2.5 D
    • (d) + 2.5 D
    उत्तर देखें

    उत्तर: (c)

80. 80. A sound source of frequency 440 Hz is tied to the end of a 1.5 m long string and rotated in a horizontal plane at an angular velocity of 20 radians/sec. What is the frequency range of the sound heard by a listener standing for away ? (Velocity of sound in air = 330 m/s)

    • (a) 440 – 480 Hz
    • (b) 403 – 484 Hz
    • (c) 400 – 500 Hz
    • (d) 408 – 490 Hz
    उत्तर देखें

    उत्तर: (b)

81. 81. If the polarizing angle for a medium is 60°, what will the critical angle be ?

    • (a) 60°
    • (b) cos⁻¹ (1/√3)
    • (c) sin⁻¹ (1/√3)
    • (d) tan⁻¹ (1/√3)
    उत्तर देखें

    उत्तर: (c)

82. 82. An organ pipe of length 0.5 m is open at both ends. What is the frequency of its fundamental note ? (Velocity of sound in air = 350 m/s)

    • (a) 350 Hz
    • (b) 175 Hz
    • (c) 700 Hz
    • (d) 450 Hz
    उत्तर देखें

    उत्तर: (a)

83. 83. 27 identical mercury drops are each charged to 10 V potential. Then they are merged to form one large drop. What will be the potential of the large drop ?

    • (a) 270 V
    • (b) 30 V
    • (c) 60 V
    • (d) 90 V
    उत्तर देखें

    उत्तर: (d)

84. 84. Three equal resistances R are connected in the form of a triangle. The equivalent resistance between any two corners is

    • (a) 3R
    • (b) (3/2)R
    • (c) (1/3)R
    • (d) (2/3)R
    उत्तर देखें

    उत्तर: (d)

85. 85. Two long parallel wires are at a distance 2R from each other. If currents i and 2i flow through them in opposite directions, what is the magnetic field B at the midpoint between them ?

    • (a) μ₀i/(2πR)
    • (b) 3μ₀i/(2πR)
    • (c) 2μ₀i/(2πR)
    • (d) 3μ₀i/(πR)
    उत्तर देखें

    उत्तर: (b)

86. 86. Which is a symbol of the n-p-n transistor ?

    • (a)
    • (b)
    • (c)
    • (d)
    उत्तर देखें

    उत्तर: (b)

87. 87. An element ₈₄X²⁰² emits an α – particle and then a β⁻ particle. If the final product is ₐYᵇ, then a and b are

    • (a) 82, 198
    • (b) 83, 198
    • (c) 82, 199
    • (d) 83, 199
    उत्तर देखें

    उत्तर: (b)

88. 88. Which of the following is incorrect ?

    • (a) Neutral pi-meson disintegrates into two photons
    • (b) Average life of +ve and –ve pi-mesons is about 10⁻⁸ secs.
    • (c) Mass of neutral pi-meson is about 264 times that of electron
    • (d) +ve pi-meson is a stable particle
    उत्तर देखें

    उत्तर: (d)

89. 89. Newton’s formula for the focal length of a thin lens is

    • (a) xx′ = –ff′
    • (b) xx′ = ff′
    • (c) xx′ = –f²f′
    • (d) xx′ = f/f′
    उत्तर देखें

    उत्तर: (b)

90. 90. A prism of angle 60° has minimum deviation angle of 30°. What is the refractive index of the material of the prism ?

    • (a) 2
    • (b) √2
    • (c) √(3/2)
    • (d) √3
    उत्तर देखें

    उत्तर: (b)

91. 91. If |A⃗ × B⃗| = AB, then angle between A⃗ and B⃗ is

    • (a) 0
    • (b) π/4
    • (c) π/2
    • (d) π
    उत्तर देखें

    उत्तर: (c)

92. 92. Boolean expression for AND gate is

    • (a) Y = A + B
    • (b) Y = A . B
    • (c)
    • (d)
    उत्तर देखें

    उत्तर: (b)

93. 93. What is the relation between orbital and escape velocities (v₀ and vₑ) ? (orbit is close to earth’s surface)

    • (a) vₑ = √2 v₀
    • (b) vₑ = √3 v₀
    • (c) vₑ = √5 v₀
    • (d) vₑ = √7 v₀
    उत्तर देखें

    उत्तर: (a)

94. 94. Equation for Bernoullis Theorem is

    • (a) P + ρv² + ρgh = constant
    • (b) P + mv² + mgh = constant
    • (c) P + ½ρv² + ρgh = constant
    • (d) P + ½mv² + mgh = constant
    उत्तर देखें

    उत्तर: (c)

95. 95. If a simple pendulum is falling freely under gravitational force of attraction, its time period will be

    • (a) 2π√(l/g)
    • (b) 2π√g
    • (c) ∞
    • (d) 0
    उत्तर देखें

    उत्तर: (c)

96. 96. Physical quantities which have same units are

    • (a) Force and work
    • (b) Pressure and stress
    • (c) Pressure and strain
    • (d) Pressure and volume
    उत्तर देखें

    उत्तर: (b)

97. 97. The dimensions of constant ‘a’ in Van der Waal’s equation is

    • (a) MLT⁻²
    • (b) ML⁻¹T⁻³
    • (c) ML⁵T⁻²
    • (d) L⁶
    उत्तर देखें

    उत्तर: (c)

98. 98. The diameter of the objective of a telescope is d and light of wavelength λ is being used. What will be the limit of resolution ?

    • (a) 1.22λ/d
    • (b) λ/d
    • (c) d/(1.22λ)
    • (d) 1.22d/λ
    उत्तर देखें

    उत्तर: (a)

99. 99. When two lenses are in contact, the condition for achromatism is

    • (a) ω₁/f₁ = ω₂/f₂
    • (b) ω₁f₁ = ω₂f₂
    • (c) ω₁/f₁ + ω₂/f₂ = 0
    • (d) ω₁f₁ = – ω₂f₂
    उत्तर देखें

    उत्तर: (c)

100. 100. Velocity of sound will be highest in

     • (a) Air
     • (b) Water
     • (c) Vacuum
     • (d) Steel
     उत्तर देखें

     उत्तर: (d)

101. 101. Two sound sources have equations y₁ = 0.25 Sin 316 t and y₂ = 0.25 Sin 310 t respectively. If the listener hears both together how many beats will be hear per second ?

     • (a) 6
     • (b) 6/π
     • (c) 3/π
     • (d) 3π
     उत्तर देखें

     उत्तर: (c)

102. 102. An AC source (V volts) sends current through a series L, C, R circuit. If voltages V_L, V_C, V_R are measured across L, C, R, then

     • (a)
     • (b)
     • (c)
     • (d)
     उत्तर देखें

     उत्तर: (d)

103. 103. In photoelectric effect, the rate of emission of photoelectrons depends on

     • (a) Intensity of radiation
     • (b) Frequency of radiation
     • (c) Both (A) and (B) above
     • (d) None of the above
     उत्तर देखें

     उत्तर: (a)

104. 104. If the rms potential difference across a 15 kΩ resistance is 16 V, the maximum current flowing is

     • (a) 15 mA
     • (b) 1 mA
     • (c) 10 mA
     • (d) 1.5 mA
     उत्तर देखें

     उत्तर: (d)

105. 105. A circular coil of N turns and radius r is placed initially with its plane perpendicular to a uniform magnetic field B. It is then rotated through 90°. How much charge flows through the coil ? Coil resistance is R.

     • (a) Zero
     • (b) πN²r B/R
     • (c) 2πr N²B/R
     • (d) πr² NB/R
     उत्तर देखें

     उत्तर: (d)

106. 106. A light wave enters glass from air. What does not change ?

     • (a) Frequency
     • (b) Wavelength
     • (c) Velocity
     • (d) All the above change
     उत्तर देखें

     उत्तर: (a)

107. 107. A transformer heats up after long use mainly because of

     • (a) Current in the coils
     • (b) Hysteresis loss
     • (c) Electromagnetic radiation
     • (d) External sources
     उत्तर देखें

     उत्तर: (b)

108. 108. The Balmer series of Hydrogen is found in which region ?

     • (a) Infra-red
     • (b) Ultraviolet
     • (c) Visible
     • (d) X-ray
     उत्तर देखें

     उत्तर: (c)

109. 109. A straight wire of length L has current I flowing through it. A constant magnetic field B, parallel to the wire, is applied. What is the force on the wire ?

     • (a) Zero
     • (b) BLI
     • (c) B²LI
     • (d) BL²I
     उत्तर देखें

     उत्तर: (a)

110. 110. Which statement is incorrect ?

     • (a) Two equipotential surfaces cannot intersect
     • (b) Line integral of electric field on an equipotential surface is a finite constant
     • (c) Electric field at surface of a conductor is always perpendicular to it
     • (d) Work done in moving a charge on an equipotential surface is zero
     उत्तर देखें

     उत्तर: (b)

111. 111. After collision of photon with an electron the photon has

     • (a) Higher frequency
     • (b) Larger wavelength
     • (c) More energy
     • (d) Lesser velocity
     उत्तर देखें

     उत्तर: (b)

112. 112. The interaction energy of the charges in the set-up below will be

     • (a) q²/(4πε₀a) (√2 – 4)
     • (b) q²/(4πε₀a) (√2 + 4)
     • (c) q²/(4πε₀a) 2√2
     • (d) q²/(4πε₀a) 4√2
     उत्तर देखें

     उत्तर: (a)

113. 113. If μ₀ = 1.544 and μ_E = 1.558 then the thickness of a quarter wave plate for λ = 6500Å is

     • (a) 0.25 μm
     • (b) 0.38 μm
     • (c) 10.0 μm
     • (d) 11.6 μm
     उत्तर देखें

     उत्तर: (d)

114. 114. For diffraction at a single slit, the width of the central maximum is ________ the wavelength of light.

     • (a) Proportional to
     • (b) Proportional to the square of
     • (c) Inversely proportional to
     • (d) Independent of
     उत्तर देखें

     उत्तर: (a)

115. 115. Water rises to a height of 10 cm in a capillary. Mercury falls to a depth of 3.42 cm in same capillary. If the relative density of mercury is 13.6 and its angle of contact is 135°, the ratio of surface tensions of water and mercury is

     • (a) 0.05
     • (b) 0.10
     • (c) 0.15
     • (d) 0.20
     उत्तर देखें

     उत्तर: (c)

116. 116. The electric field components of a plane electromagnetic wave are What is the nature of the wave ?

     • (a) Right elliptical
     • (b) Left elliptical
     • (c) Right circular
     • (d) Left circular
     उत्तर देखें

     उत्तर: (a)

117. 117. The mass ratio of two planets is x and the density ratio is y. What is the ratio of the acceleration due to gravity on their surfaces ?

     • (a) x²/y
     • (b)
     • (c) x²y
     • (d)
     उत्तर देखें

     उत्तर: (d)

118. 118. If the values of M and A are experimentally measured as 3.00 units and 2.820 units respectively, what will be the percentage error in the calculated value of Y (=M/A) ?

     • (a) 0.036%
     • (b) 0.072%
     • (c) 0.36%
     • (d) 0.72%
     उत्तर देखें

     उत्तर: (c)

119. 119. If I = I₀ sin² (2πt/T), then what is the average value of I between t = 0 and t = T/2 ?

     • (a) √2 I₀
     • (b) I₀/√2
     • (c) I₀/2
     • (d) I₀
     उत्तर देखें

     उत्तर: (c)

120. 120. A ring of radius R is uniformly charged with charge q. What is the electric potential V at a point on the axis, at a distance x from the centre ?

     • (a)
     • (b)
     • (c)
     • (d)
     उत्तर देखें

     उत्तर: (b)

121. 121. Which of the following is a reversible process ?

     • (a) Production of heat by passing current through a resistance
     • (b) Conduction of heat from hot body to cold body
     • (c) Infinitely slow changes in the pressure and volume of the working substance
     • (d) Forcing a real gas through a porous plug while keeping them insulated from the environment
     उत्तर देखें

     उत्तर: (c)

122. 122. The mass and radius of the earth are M and R. How long should one day be so that a person feels weightless on the equator ? (acceleration due to gravity = g)

     • (a) 2π√(R/g)
     • (b) (1/2π)√(g/R)
     • (c) (1/2π)√(g/MR)
     • (d) 2π√(MR²/g)
     उत्तर देखें

     उत्तर: (a)

123. 123. An adiabatic process is also known as

     • (a) Isoentropic
     • (b) Isothermal
     • (c) Isobaric
     • (d) Isochoric
     उत्तर देखें

     उत्तर: (a)

124. 124. A small solid sphere is dropped into a viscous liquid. It finally moves with a constant velocity which is called

     • (a) Escape velocity
     • (b) Terminal velocity
     • (c) Critical velocity
     • (d) Reynold velocity
     उत्तर देखें

     उत्तर: (b)

125. 125. Three vectors A⃗, B⃗ and C⃗ will be coplanar only if

     • (a) A⃗.B⃗ = B⃗.C⃗ = A⃗.C⃗ = 0
     • (b) A⃗.(B⃗ × C⃗) = 0
     • (c) A⃗ × (B⃗ × C⃗) = 0
     • (d) (A⃗.B⃗) × C⃗ = 0
     उत्तर देखें

     उत्तर: (b)