universe & solar system section 2 MCQ Questions & Answers Detailed Explanation

Answer: (d)

Answer: (a)

The colour of the star is an indication of its temperature. The glowing is caused by something called Black-Body radiation, which has to do with the heat energy trying to radiate away in more and more energetic wavelengths.

Red stars are relatively cool at only a few thousand degrees Celsius, white stars are hot at about ten thousand degrees, and blue stars are the hottest.

Answer: (d)

Albedo also varies according to the angle of incidence of the Sun Rays being higher for slanting rays and lower for vertical or nearly vertical rays. From this we can derive that albedo will be relatively higher during early morning and late evening because at both times, Sun rays are slanting.

Answer: (b)

Answer: (d)

1. The Sial refers to the composition of the upper layer of the Earth’s crust, namely rocks rich in silicates and aluminium minerals.
2. Sima is the name for the lower layer of the Earth’s crust. This layer is made of rocks rich in magnesium silicate minerals.
3. Nife is the innermost layer of earth.
4. Fossils are the remains of dead plants and animals trapped in rocks.

Answer: (a)

The surface temperature of Sun is 5778 K or approximately 6000 K.