The Universe (Part-4)

Total Questions: 50

1. Nix and Hydra are the moons of - [U.P.U.D.A./L.D.A. (Spl) (Mains) 2010]

Correct Answer: (a) Pluto
Solution:Pluto is a dwarf planet of the Solar system, it has five satellites (moons). According to the distance from the Pluto (from inner to outer side their names are Charon, Styx, Nix, Kerberos and Hydra. Charon is the biggest satellite.

There are 95 known satellites of Jupiter and till now there is no information about the existence of any satellite of Venus and Mercury.

2. When did man first land on the Moon? [M.P.P.C.S. (Pre) 1995]

Correct Answer: (d) 1969
Solution:On 20th July 1969 for the first time, man landed on Moon. Three Astronauts sent with Apollo-11 mission to the moon were Neil Armstrong, Michel Collins and Edvin Buzz Aldrin Junior.

Among these astronauts, only Niel Armstrong and Edwin Aldrin walked on the surface of the moon. On 16 July 1969, initiating its flight from Cape Kennedy Space Centre, Florida (U.S.A.). Apollo-11 landed on the 'Sea of Tranquility upon the Moon on 20 July 1969.

On 21 July 1969 it started return journey from the Moon towards the Earth and finally landed in the Pacific Ocean on 24 July, 1969.

3. The "Sea of Tranquility" lies on - [M.P.P.C.S. (Pre) 1995]

Correct Answer: (d) Moon
Solution:Area of large the black patch as seen from the Earth is called Lunar Mare or the "Sea of Tranquility" which is found on the large area of the Moon where spacecraft Apollo-11 landed in 1969.

Neil Armstrong was the first person to touch the surface of the Moon, followed Edwin Aldrin Junior.

4. Consider the following statements: [I.A.S. (Pre) 2005]

Assertion (A): The same face of the Moon always faces the Earth.

Reason (R) : The Moon completes one rotation around its own axis in 23 and half days which is about the same time that it takes to orbit the Earth.

Correct Answer: (c) (A)' is true, but (R) is false.
Solution:The orbit of the Moon around the Earth is elliptical and tilted and therefore we can see only 59% of the Moon's surface at a time. Moon takes 27 days, 7 hours, 43 minutes to rotate on its axis.

This is also the time of one revolution of the Moon around the Earth. This is the reason why we see always the same face of the Moon. Therefore, statement A is correct but reason R is incorrect.

5. Consider the following statements and answer the question with the help of codes given below: [U.P.P.C.S. (Pre) 2006]

Assertion (A): Only one side of the moon's surface is visible from the earth.

Reason(R) : The period of rotation of the moon on its axis is equal to the period of its revolution around the earth.

Code:

Correct Answer: (a) Both (A) and (R) are true, and (R) is the correct explanation of (A).
Solution:We see only one side of the Moon's surface from earth as Moon's orbit around the earth is elliptical and tilted. Earth's satellite Moon rotates on its axis and revolves around the Earth in the same time of 27 days, 7 hrs and 43 minutes.

So only one side of the moon's surface is visible from the earth, therefore statement 'A' is correct and reason 'R' is also correct. Therefore reason (R) explains statement (A) correctly.

6. On the surface of the moon, two persons cannot listen to each other as [U.P.P.C.S. (Pre) 2003]

Correct Answer: (b) There is no atmosphere on the Moon,
Solution:For communication of sound waves, a material medium is needed and the atmosphere is such a medium. At the moon the atmosphere is absent. That is why two people cannot listen to each other on the Moon.

7. When does a Lunar eclipse take place? [M.P.P.C.S. (Pre) 1994]

Correct Answer: (b) When the earth comes between the sun and the moon.
Solution:When the Earth comes between the Moon and the Sun, the Moon gets into the dark due to obstruction of light rays coming from the Sun by the Earth. Type of the Lunar eclipse and its length depends upon the relative position of the Moon and its orbital path. A lunar eclipse only occurs on the full moon day.

8. Lunar Eclipse is caused when [Uttarakhand Lower Sub. (Pre) 2010]

Correct Answer: (b) Earth comes between Sun and Moon
Solution:When the Earth comes between the Moon and the Sun, the Moon gets into the dark due to obstruction of light rays coming from the Sun by the Earth. Type of the Lunar eclipse and its length depends upon the relative position of the Moon and its orbital path. A lunar eclipse only occurs on the full moon day.

9. In which situation lunar eclipse occurs ? [M.P.P.C.S. (Pre) 1992]

Correct Answer: (c) Full Moon
Solution:When the Earth comes between the Moon and the Sun, the Moon gets into the dark due to obstruction of light rays coming from the Sun by the Earth. Type of the Lunar eclipse and its length depends upon the relative position of the Moon and its orbital path. A lunar eclipse only occurs on the full moon day.

10. The main condition responsible for greater brightness of the moon on the full moon day of 22nd Dec. 1999 was: [R.A.S./R.T.S.(Pre) 1999]

Correct Answer: (d) Perigee
Solution:The main condition responsible for greater brightness of the moon on the full moon day of 22nd December, 1999 was perigee. Perigee is the closest point to the Earth.