# UPSC SSC :: General Studies :: Physics

## Home UPSC SSC / General Studies Questions and Answers

76 .The length of the pendulum isdoubled and the mass of its bob is halved.Its time sperod would
become double
become half
become $\sqrt2$ times
remain the same

77 .Vibration magnetometer works on the principle of
torque acting on the bar magnet
force acting on the bar magnet
both the force and the torque acting on the bar magnet
none of these

78 .Which one of the following is the most stable ecosystem?
Mountain
Ocean
Forest
Desert

79 .The primary colours in phothgraphy are
red, blue, yellow
red, yellow, green
red, blue, green
red, green, cyan

80 .Cosmic rays
are charged particles
are uncharged particles
can be charged as well as unchanged
None of the above

81 .Myopia is due to
shortening of eye ball
irregular changes in the focal length of the eye lens
older age
elongation of eye ball

82 .A motor converts
mechanical energy into electrical energy
mechanical energy into sound energy
electrical energy into mechanical energy
None of these

83 .Which of the following is not caused by atmospheric refraction of light?
Sun appearing higher in the sky than it actually is
Sun becoming visible two or three minutes before actual sunrise
Sun appearing red at sunset
Twinkling of stars at night

84 .What is the difference between aCFL and an LED LAMP?
( 1 ) Toproduce light, a CFL uses mercuryvapour and phosphor while an LED lampuses semi- conductor material.
( 2 ) The average life span of a CFL ismuch longer than of and LED lamp.
( 3 ) A CFL is LESS energy -efficient ascompared to an LED lamp.
Which of the statements given aboveis/are correct?

1 only
2 and 3
1 and 3
1, 2 and 3

85 .The mercury and sodium street lamps light up because of.
Electron absorption
Electron emission
Atomic emission
Atomic absorption

86 .The least penetrating power ray is
Ray
X â€“ Ray
Î³ Ray
Ray

87 .Different objects at different distances are seen by the eye. The paramenter athe remains. Constent is
the focal length of the eye lens
the object distance from the eye lens
the radii of curvature of the eye lens
the image distance from the eye lens

88 .Colours of thin films are due to
dispersion of light
interference of light
absorption of light
scattering of light

89 .The clouds float in the atmosphere because of their low The clouds float in the atmosphere because of their low
1

90 .X- rays were discovered by-
Roentgen
Becquere
Curie
Van lane