universe & solar system section 12 MCQ Questions & Answers Detailed Explanation

Answer: (b)

A. The smallest planet of the solar system is – Pluto

B. The largest planet of the solar system is – Jupiter

C. The planet second from the Sun in the solar system is – Venus

D. Planet nearest to the Sun is – Mercury.

Answer: (c)

The group of stars arranged in a definite pattern is called constellation. In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, which are patterns formed by prominent stars within apparent proximity to one another on Earth’s night sky.

Answer: (d)

Like the other planets in our solar system, Venus rotates about its axis.

However, Venus is the only planet that rotates from east to west instead of west to east. This means, that if we lived on Venus, the Sun would appear to rise in the west in the morning, and set in the east in the evening. Venus rotates in what is called retrograde motion.

Answer: (d)

Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, an ultraviolet light.

On Earth, sunlight is filtered through the Earth’s atmosphere, and is obvious as daylight when the Sun is above the horizon.

Answer: (b)

The planet Pluto has been declared as a dwarf planet in the summit held in Prague. In August 2006 the International Astronomical Union (IAU) downgraded the status of Pluto to that of a “dwarf planet.”

This means that from now on only the rocky worlds of the inner Solar System and the gas giants of the outer system will be designated as planets.

Answer: (a)

The principle of Blackhole was enunciated by S. Chandrashekhar. A Black Hole is a region of space-time from which gravity prevents anything, including light, from escaping. The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole, there is a mathematically defined surface called an event horizon that marks the point of no return.

The hole is called “black” because it absorbs all the light that hits the horizon, reflecting nothing, just like a perfect black body in thermodynamics.