A. Visible light
B. Infrared radiation
C. X-rays and gamma rays
D. Ultraviolet radiation

A. 60-80 db
B. 45-60 db
C. 100-120 db
D. 25-45 db

A. 21.5
B. 23.5
C. 66.5
D. 90

A. air
B. steel
C. vacuum
D. water

A. rotary engines
B. external combustion engines
C. turbine engines
D. reaction engines

A. Pollution in houses in tropical regions
B. Trapping of solar energy due to
atmospheric oxygen
C. Trapping of solar energy due to
atmospheric carbon dioxide
D. Cultivation in green houses so as to check
pollution.

A. It is much smaller than the earth
B. It revolves round the earth
C. It draws light from the sun via the earth
D. It remains in position due to the
gravitational pull of the earth.

A. 23 hours, 56 minutes, 4.09 seconds
B. 23 hours, 58 minutes, 29.5 seconds
C. 23 hours, 59 minutes, 7.5 seconds
D. 23 hours, 59 minutes, 18 seconds

A. Poles
B. Tropic of Cancer
C. Equator
D. Tropic of Capricorn

A. 3.6 secs
B. 2 secs
C. 1.3 secs
D. 1 sec