Quiznetik

A Level Physics | Set 4

1. 1 V is equal to {{}}

Correct : A. 1 J C-1

2. Ideal resistance of ammeter is

Correct : C. 0 Ω

3. Density of water in kg m-3 is {{}}

Correct : A. 1000

4. Normal force acting per unit cross sectional area is called

Correct : B. pressure

5. Ratio of tensile to strain is

Correct : A. Young's modulus

6. Gradient of force-extension graph is

Correct : D. force constant

7. Energy in deformed solid is called

Correct : D. strain energy

8. Units of stress are

Correct : C. Pascal

9. Concentration of matter in a material is

Correct : C. density

10. Units of strain are

Correct : D. no units

11. Stress is force applied on

Correct : B. cross sectional area

12. The larger the spring constant, the spring would be more

Correct : B. stiffer

13. Height of atmosphere, if atmospheric density is 1.29 kg m-3 and atmospheric pressure is 101 kPa, is {{}}

Correct : B. 7829.4 m

14. Pressure in fluid depends upon

Correct : D. all of above

15. As depth increases, pressure in a fluid

Correct : A. increases

16. If extension in spring is proportional to load applied, then material obeys

Correct : D. Hooke's law

17. If a spring is squashed, then forces are

Correct : B. compressive

18. Fractional increase in original length is called

Correct : B. strain

19. If a force of 50 N is applied across the cross-sectional area of 5 × 10 - 7m2 then stress applied on it is {{}}

Correct : A. 1 × 10 8 Pa

20. Mass of steel sphere having density 7850 kg m-3 and radius 0.15 m is

Correct : C. 110.9 kg

21. In a force-extension graph, force is taken along horizontal axis because

Correct : A. force is independent variable

22. Extension and applied force are

Correct : A. directly proportional

23. 1 Pa is equal to

Correct : D. 1 N m-2

24. Spring constant of spring is also called

Correct : C. stiffness

25. Tensile strain is equal to

Correct : C. Extension per unit length

26. In elastic collisions,

Correct : C. both of the momentum and total kinetic energy are conserved.

27. Total angular momentum of a body is given by

Correct : A. I × ω; where I: moment of inertia of the body, ω: angular velocity

28. Force that acts on a mass of 1 g and gives it an acceleration of 1 cm s -2 is defined as {{}}

Correct : B. 1 dyne

29. An object moving in a circle of radius ‘r’ with a constant speed ‘v’ has a constant acceleration towards the center equal to

Correct : A. v²⁄r

30. Einstein's mass-energy relationship states that if the mass decreases by Δm, the energy released ΔE is given by {{}}

Correct : B. ΔE = Δm × c², where "c" denotes the speed of light.

31. Bernoulli's principle states that, for streamline motion of an incompressible non-viscous fluid:

Correct : D. the pressure at any part + the kinetic energy per unit volume + the potential energy per unit volume = constant

32. While Young's modulus ‘E’ relates to change in length and bulk modulus ‘K’ relates to change in volume, modulus of rigidity ‘G’ relates to change in:

Correct : C. shape

33. Young's modulus is defined as

Correct : B. tensile stress/tensile strain

34. Velocity of escape is equal to

Correct : D. √(2gr); where r: radius of Earth or any other planet for that matter, g: gravitational field strength

35. Speed ‘v’ with which wave travels through a medium is given by

Correct : C. √(modulus of elasticity/density of the medium

36. Hooke's law states that

Correct : A. the extension is proportional to the load when the elastic limit is not exceeded

37. Dimensions of strain are {{}}

Correct : D. It's a dimensionless quantity

38. Due to energy dissipation by viscous forces in air, if simple harmonic variations of a pendulum die away after some time, then oscillation is said to be:

Correct : C. damped

39. At ‘yield point’ of a copper wire

Correct : B. the load has already exceeded the elastic limit and the material has become plastic

40. Stationary waves are also called

Correct : B. standing waves

41. When the work done in moving a particle round a closed loop in a field is zero, the forces in the field are called

Correct : C. Conservative forces

42. Substances that elongate considerably and undergo plastic deformation before they break are known as

Correct : C. ductile substances

43. 1 torr is equal to

Correct : B. 1 mm Hg

44. Velocity of sound waves through any material depends on

Correct : B. the material's density ‘d’ as well as its modulus of elasticity ‘E’

45. Period of simple harmonic motion of a spiral spring or elastic thread is given by

Correct : D. T = 2π × √(extension produced/gravitational field strength

46. In order to slip one surface over another, maximum frictional force has to be overcome, this maximum frictional force between the two surfaces is also known as

Correct : C. limiting frictional force

47. Van der Waals derived an expression for the ‘pressure defect’, if the observed pressure is denoted as ‘p’ and volume is denoted as ‘V’, the gas pressure in the bulk of the gas is equal to:

Correct : B. p + a/(V²); where a: constant for the particular gas

48. "Upthrust = Weight of the liquid displaced" is known as

Correct : B. Archimedes' Principle

49. Assuming uniform density of the core, the acceleration due to gravity below the Earth's surface is

Correct : D. directly proportional to the distance from the center of the Earth

50. When a gas or a liquid is subjected to an increased pressure, the substance contracts, the bulk strain is defined as

Correct : C. change in volume ⁄ original volume

51. Tensile stress is equal to

Correct : A. Force per unit area

52. Dimensions of relative density are

Correct : C. It has no dimensions, since it's a ratio of two densities

53. Dimensions of gravitational constant ‘G’ are: {{}}

Correct : A. [M]-1[L]3[T]-2

54. A person of mass ‘m’ kg jumps from a height of ‘h’ meters, he will land on the ground with a velocity equal to:

Correct : A. √(2 × g × h

55. In linear motion, the energy is given by 1⁄2mv 2. Similarly, in rotational motion, the rotational energy is given by {{}}

Correct : C. 1/2 × I × ω²; where I: moment of inertia of the body, ω: angular velocity

56. Boyle's law states that

Correct : A. pressure of a gas is inversely proportional to its volume i.e. P × V = constant

57. Isothermal bulk modulus is equal to

Correct : B. Pressure

58. Adiabatic bulk modulus is equal to:

Correct : A. Υ × P; where Υ: the ratio of the specific heat capacities of the gas, P: pressure

59. Bernoulli's principle shows that, at points in a moving fluid where the potential energy change is very small

Correct : B. the pressure is low where the velocity is high and conversely, the pressure is high where the velocity is low

60. 1 N (newton) is equal to {{}}

Correct : D. 105 dynes

61. Torricelli's theorem states that the velocity ‘v’ of the liquid emerging from the bottom of the wide tank is given by √(2gh). In practice, this velocity is:

Correct : C. lesser than √(2gh

62. Dimensions of Young's modulus are {{}}

Correct : D. [M] [L]-1[T]-2

63. Kepler's 3rd law states that...

Correct : C. the squares of the periods of revolution of the planets are proportional to the cube of their mean distance from sun

64. Gradual decrease in x-ray beam intensity as it passes through material is called

Correct : A. attenuation

65. Attenuation coefficient of bone is 600 m-1 for x-rays of energy 20 keV and intensity of beam of x-rays is 20 Wm-2, then intensity of beam after passingthrough a bone of 4mm is {{}}

Correct : D. 1.8 Wm-2

66. For protons, the gyromagnetic ratio has the value {{}}

Correct : B. 2.68 × 108rads-1 T-1

67. Energy passing through unit area is

Correct : A. intensity of x-ray

68. speed of ultrasound depends upon

Correct : C. material

69. Bones look white in x-ray photograph because

Correct : C. they are good absorbers of x-rays

70. Larmor frequency depends upon the

Correct : C. both A and B

71. Acoustic impedance of human skin is {{}}

Correct : B. 1.71 × 106 kg m-2 s-1

72. In the best piezo-electric substances, the maximum value of strain is about

Correct : D. 0.1 %

73. With gel between skin and transducer percentage of reflected intensity of ultrasonic is

Correct : A. 0.03%

74. Attenuation coefficient depends on

Correct : C. energy of x-ray photons

75. x-rays are filtered out of human body by using

Correct : D. aluminum absorbers

76. Wavelength of x-rays is in range

Correct : A. 10 -8 to 10 -13 m

77. If fast moving electrons rapidly decelerate, then rays produced are

Correct : D. x-rays

78. As the x-rays pass through matter, it's intensity

Correct : B. decreases

79. X-rays have

Correct : C. both A and B

80. Acoustic impedance is defined as

Correct : B. ρc

81. A sound wave which has frequency higher than the upper limit of human hearing is

Correct : B. ultrasonic

82. Fatty tissues have

Correct : D. relaxation times of several hundred milliseconds

83. Angular frequency of precision is called

Correct : C. Larmor frequency

84. Scattered x-ray beams approach the detector screen

Correct : D. at an angle

85. Maximum energy an x-ray photon can have is {{}}

Correct : C. eV

86. Soft x-rays have

Correct : B. low energies

87. Intensity of x-rays can be increased by increasing

Correct : B. current

88. Bone thickness is equal to {{}}

Correct : A. cΔt/2

89. Hardness of x-ray beam can be increased by increasing

Correct : A. voltage

90. In x-ray production, the kinetic energy of an electron arriving at anode is

Correct : B. 200 keV

91. Change in speed of ultrasound causes

Correct : C. refraction

92. Type of x-rays used to detect break in bone is

Correct : A. hard

93. Wavelength of 2.0 MHz ultrasound waves in tissue is

Correct : A. 7.5 × 10-4 m

94. Intensifier screens reduces the patient's exposure to x-rays by a factor of

Correct : C. 100-500

95. Contrast media consist of elements with

Correct : B. higher atomic number

96. Thickness of material which decreases intensity of x-ray material to half of original value is

Correct : B. half thickness

97. A good x-ray source should produce x-rays of narrow beam and

Correct : A. parallel x-rays

98. Speed of Earth when a rock of mass 60 kg falling towards Earth with speed of 20 m s-1 is {{}}

Correct : C. −2.0 × 10-22 m s-1

99. Force exerted by bat on ball if it strikes a ball of mass 0.16 kg initially hits bat with speed of 25 m s-1 with time impact of 0.003 s is {{}}

Correct : B. 1333.33 N

100. Momentum of electron having mass 9.1 × 10 -31 kg and velocity 2.0 ×107 is {{}}

Correct : A. 1.91 × 10-23