# UPSC SSC :: General Studies :: Physics

## Home UPSC SSC / General Studies Questions and Answers

181 .Critical angle of light passing from glass to water is minimum for
interference
total reflection
scattering
double refraction

182 .Instrument used to study the behavior of a vibrating string is:
Hygrometer
Sonmeter
Barometer
Hydrometer

183 .X - rays are used for the study of crystal structure because
X- rays are completely absorbed by the crystal
The wavelength of X â€“ rays is of the same order of magnitude as the interatomic spacing in crystals
The wavelength of X â€“ rays is very small in comparison with the interatomic spacing in crystals
The crystals are completely transparent to X â€“ rays

184 .In a healthy human eye, the focusing is done by the
To and from movement of the eye lens
Changing curvature of the retina
Change in the convexity of the lens throught ciliary muscles
Change in the refractive index of the eye fluid

185 .Decibel is the unit used for measuring
Speed of light
Intensity of heat
Intensity of sound

186 .A digita signal:
is less reliable than analog signal
is more reliable than analog signal
is equally reliable as the analog signal
None of the above

187 .The 'greenhouse effect' refers to:
Increasing agricultural yields
Gradual warming of the earth's surface
Build-up of toxic airborne pollutants
Reduction in the earth's ozone layer

188 .The resistance of a wire is R. It is stretched uniformly so that its length is doubled. The resistance now becomes
2R
R/2
4 R
R/4

189 .Consider the followingelectromagnetic waves
1. X- rays
2. Y Rays
3. Microwaves
What is the correct sequence in the orderof their increasing energy?

4, 3, 1 and 2
1, 3, 2 and 4
4, 2, 1 and 3
1, 4, 3 and 2

190 .The core of an electromagnet is made of soft iron because soft iron has
small susceptibility and small retentivity
large susceptibility and small retentivity
large density and large retentivity
small density and large retentivity

191 .The quality of sound produced by an instrument depends on the
frequency
intensity
number of overtones
none of these

192 .The concentration of pollutants in atmosphere is generally expressed in:
Parst per billion
Kilogram per square metre
Parts per trillion
Parst per million

193 .The largest ecosystem of the Earth is-
Biosphere
Hydrosphere
Lithosphere
Biome

194 .The product of conductivity and resistivity of a conductor
Depends on pressure applied
Depends on current flowing through conductor
is the same for all conductors
Varies from conductor to conductor

195 .In an isothermal expansion of a gas
a pressure remains constan
temperature remains constant
density remains constant
None of these