The most abundant element is Earth’s curst is ?
A. Oxygen
B. Hydrogen
C. Carbon dioxide
D. Silicon
Twinkling of stars is caused by?
A. Reflection of light
B. Polarization of light
C. Refraction of light
D. Interference of light
The most abundant element in the universe is?
A. Oxygen
B. Hydrogen
C. Carbon dioxide
D. None of these
Which of the following atmosphere layers help in radio communication?
A. Exosphere
B. Ionosphere
B. Troposphere
D. Stratosphere
Monsoon is caused by———-?
A. Seasonal reversal of winds
B. Revolution of earth
C. Movement of clouds
D. Rise in temperature
Where do most of asteroids lie
A. In asteroid belt between the orbits of Mars and Jupiter
B. In asteroid belt between the orbits of Mars and Venus
C. In asteroid belt between the orbits of Jupiter and Venus
D. Everywhere in the sky
Which of the following explains the reason why there is no total eclipse of the sun?
A. Size of the earth is relation to that of moon
B. Orbit of the moon around earth
C. Direction of rotation of earth around sun
D. Area of the sun covered by the moon