universe & solar system section 8 MCQ Questions & Answers Detailed Explanation

Answer: (a)

The earth is nearest to the sun on about January 3rd. Earth is farthest from the sun on about 4th July.

Answer: (a)

The Coriollis effect is the apparent deflection of global winds, ocean currents that moves freely across the Earth’s surface. The deflection is due to the rotation of the Earth on its axis.

Answer: (a)

A supernova is a stellar explosion that is more energetic than a nova. During this short interval, a supernova can radiate as much energy as the Sun is expected to emit over its entire life span.

The explosion expels much or all of a star's material at a velocity of up to 30,000 km/s (10% of the speed of light).

Answer: (c)

The inexhaustible source of energy of the stars is due to the conversion of Hydrogen to Helium. In the interior of a star, the particles move rapidly in every direction because of the high temperatures present. Every so often a proton moves close enough to a nucleus to be captured, and a nuclear reaction takes place.

Only protons of extremely high energy (many times the average energy in a star such as the Sun) are capable of producing nuclear events of this kind. A minimum temperature required for fusion is roughly 10 million K. Since the energies of protons are proportional to temperature, the rate of energy production rises steeply as temperature increases.

Answer: (c)

Venus is the second planet from the sun and a close neighbor to the earth. It was named after the Roman Goddess of Beauty. Venus is usually one the brightest objects in the sky, which might be the reason it got its name. It is quite similar to the planet earth mainly in its size and a few other characteristics which is why it is often considered the Earth’s twin.

However, surface conditions are not nearly the same making it a quite inhospitable environment.

Answer: (b)