Universe - Study Mode

[#76] The energy of Sun is vested in which of the following process?
Correct Answer

(C) Nuclear Fusion

Explanation

Solution: The sun generates energy from a process called nuclear fusion. During nuclear fusion, the high pressure and temperature in the sun's core cause nuclei to separate from their electrons. Hydrogen nuclei fuse to form one helium atom. During the fusion process, radiant energy is released.

[#77] The distance of the nearest star besides the sun from the earth is ________
Correct Answer

(D) 4.2 light years

Explanation

Solution: The nearest star to the Sun from Earth is Proxima Centauri, which is part of the Alpha Centauri star system. Its distance is approximately 4.2 light years. A light year is the distance that light travels in one year, and it is a common unit used in astronomy to represent vast distances in space. Therefore, the correct answer is Option D, which is 4.2 light years.

[#78] While Venus is seen only for one to two hours either after sunset or before sunrise, Jupiter is seen for the whole night whenever it is visible in the sky. The reason for this is that ________
Correct Answer

(C) The orbit of Venus is inside the earth's orbit whereas the orbit of Jupiter lies outside the orbit of the earth

Explanation

Solution: While Venus is seen only for one to two hours either after sunset or before sunrise, Jupiter is seen for the whole night whenever it is visible in the sky. The reason for this is that the orbit of Venus is inside the earth's orbit whereas the orbit of Jupiter lies outside the orbit of the Earth.

[#79] On which of the following planets of the solar system does the sun rise in the west and set in the east?
Correct Answer

(A) Venus

Explanation

Solution: Venus rotates on its axis the opposite way that most planets rotate. That means on Venus, the sun would appear to rise in the west and set in the east. On Earth, the sun appears to rise in the east and set in the west.

[#80] What are Sun spots?
Correct Answer

(D) Dark patches on the surface of the Sun resulting from a localised fall in the temperature to about 4000 K

Explanation

Solution: A dark patch in the sun's photosphere resulting from a localized fall in temperature to about 4000 K. Most spots have a central very dark umbra surrounded by a lighter penumbra. Sunspots tend to occur in clusters and to last about two weeks.