Translate

Thursday 26 November 2015

Physics Questions And Answers

43. An equiconvex lens is prepared from a glass of refractive index 1.5. The radius of curvature of the surface is 0.5 m. The focal length of the lens is
a. 0.5 m 
b. 1.0 m 
c. 1.5 m 
d. 2.0 m

44. Which of the following types is used by computed tomography employed for visualisation of the internal structure of human body ?
a. X-Rays 
b. Sound waves 
c. magnetic resonance 
d. radio-isotopes

45. Atmospheric pressure is measured by
a. Tonometer
b. Pyrometer
c. Barometer
d. Thermometer

46. In the winter season if we touch two blocks one of iron and another of wood in the early morning then the block of iron appears to be more cold because:
a. the temperature of the iron block is less then that of the wooden block 
b. iron is a bad conductor of heat in comparison of the wood
c. iron is a bad conductor of heat is comparison of the wood >
d. the block of iron is heavier than the wooden block

47. If a bomb dropped from an airplane explodes in mid-air _________?
a. its KE increases
b. its total energy increases
c. its total energy decreases
d. its total momentum decreases

48. In which one among the following is the speed of sound maximum?  
A.  Ait at 0 degree
B.  Ait at 100 degree
C.  Water
D.  Wood

49. Which of the following is a vector quantity ?  
a. Momentum 
b. Pressure 
c. Energy 
Work 

50. A car goes straight from a point A to a point B with a velocity of 40 km/h and return back with a velocity of 60 km/h. The average velocity during the whole journey is;
a. 0 
b. 48 km/h
c. 50 km/h 
d. none

51. A light wave travelling in a transparent homogeneous medium enters another homogeneous transparent medium of higher refractive index. The speed of light in the second medium;
a. is less than that in the first medium 
b. is more than that in the first medium 
c. is the same as that in the first medium 
d. may be more or less than that in the first medium depending on the angle of incidence

52. When light waves pass from air to glass the variables affected are 
a. wavelength frequency and velocity 
b. velocity and frequency 
c. wavelength and frequecy 
d. wavelength and velocity

53. Which one of the following is printed on a commonly used fluorescent tube light?  
A.  220 K
B.  273 K
C.  65000 K
D.  9000 K

54. The water from a hand pump is warm in winter because:
a. our body is cold in winter and water appears to be warm 
b. the temperature inside the earth is higher than the atmospheric temperature 
c. inside water comes out and absorbs heat from the environment 
d. the pumping process causes friction which warms up the water 

55. Fat can be separated from milk in a cream separator because of __________?
a. cohesive force
b. gravitational force
c. centripetal force
d. centrifugal force

56. A diode can be used for?
a. amplification
b. modulation
c. detection
d. rectification

57. A person stands at the middle point of a wooden ladder which starts slipping between vertical wall and the floor of the room, while continuing to remain in a vertical plane. The path raced by a person standing at the middle point of the slipping ladder is:
a. straight line 
b. a elliptical path 
c. a circular path 
d. a parabolic path 

58. In a healthy human eye, the focussing is done by the
a. to and fro movement of the eye lens 
b. changing curvature of the retine 
c. change in the convexity of the lens through ciliary muscles 
d. change in the refractive index of the eye fluid

59. The velocity of sound produced by a vibrating body varies:
a. directly as the sq. root of density of the medium 
b. inversely as the density of the medium 
c. directly as the sq. root of frequency of the medium 
d. inversely as the frequency of the medium

60. Which colour of heat radiation represents the highest temperature ? 
a. blood red 
b. dark chery 
c. salmon 
d. white 

61. What is the relation between wavelength, frequency and velocity ?
a. velocity of wave = frequency * wavelength
b. velocity of wave = frequency/wavelength
c. velocity of wave = wavelength/frequency
d. None of above

62. Sound travels at the fastest speed in
A.steel
B.water
C.air
D.vacuum

63. Melting point of ice
a. increase with increase of pressure
b. decrease with increase of pressure
c. is independent of pressure
d. None of these


64. The value of which one of the following quantity remains same in all system of units ? 
a. Acceleration due to gravity 
b. Specific gravity 
c. pressure 
d. density 


65. The magnifying power of a telescope can be increased by
a. reducing the focal length of the eye piece 
b. increasing the diameter of the objective 
c. reducing the focal length of the objective 
d. increasing the diameter of the eyepiece

66. which one of the following statements is correct ? Transfer of heat energy from a heater coil to the cooking vessel takes place through the process of
a. convection only 
b. conduction and convection only 
c. radiation and convection only 
d. convection conduction and radiation 

67. A particle is executing simple harmonic motion. Its total energy is proportional to its:>
a. displacement from equilibrium position 
b. frequency of oscillation 
c. square of amplitude of motion 
d. velocity at equilibrium position 

68. Which of following in not a property of cathode ray.
a. Cathode rays are invisible and travel in a straight line.
b. These rays can ionise gases.
c. These rays can penetrate through thin metal foils.
d. These rays make materials cool on which they fall.

69. If the temperature inside a room is increased, the relative humidity will?
a. increase
b. decrease
c. remain unchanged
d. none of these


70. Light Emitting Diodes (LED) is used in fancy electronic devices such as toys emit
A.X-rays
B.ultraviolet light
C.visible light
D.radio waves



Answers: 

43. Answer: 0.5 m

44. Answer: X-Rays

45. Answer: Option C

46. Answer: iron is a bad conductor of heat in comparison of the wood

47. Ans. A
The kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes.

48. Answer : C.  Water

49. Answer: Momentum

50. Answer: 0

51. Answer: is less than that in the first medium

52. Answer: wavelength and velocity

53. Answer : C.  65000 K

54. Answer: the temperature inside the earth is higher than the atmospheric temperature 

55. Ans. D
The centrifugal separator was invented in 1897. By the turn of the century it had altered the dairy industry by making centralised dairy processing possible for the first time. It also allowed removal of cream and recovery of the skim milk in a fresh state.

56. Ans. D
Rectification
The most common function of a diode is to allow an electric current to pass in one direction (called the diode's forward direction), while blocking current in the opposite direction .Thus, the diode can be viewed as an electronic version of a check valve. This unidirectional behavior is called rectification, and is used to convert alternating current to direct current, including extraction of modulation from radio signals in radio receivers—these diodes are forms of rectifiers.

57. Answer: a circular path 

58. Answer: change in the convexity of the lens through ciliary muscles 

59. Answer: >inversely as the density of the medium

60. Answer: white 

61. Answer: Option A

62. Answer & Explanation Answer: Option D Explanation: No answer description available for this question. Let us discuss.

63. Ans. B
The melting point of ice at 1 atmosphere of pressure is very close to 0 °C (32 °F, 273.15 K); this is also known as the ice point.

64. Answer: Specific gravity 

65. Answer: reducing the focal length of the eye piece

66. Answer: radiation and convection only 

67. Answer: square of amplitude of motion

68. Answer: Option D

69. Ans. B
Decrease
This is because temperatures in the home can be much different than the temperature outside. This is because of that important relationship between temperature and how much maximum moisture can be in the air.

70. Answer: visible light




29- 42 bits click here 


1 comment:

  1. Thank you for giving this opportunity,Your site is very useful for every one.
    Regards:
    SarkariResults


    ReplyDelete

National Current Affairs