Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Earth has atmosphere whereas moon doesn't have any atmosphere.
Reason R: The escape velocity on moon is very small as compared to that on earth.
In the light of the above statement, choose the correct answer from the options given below :
Assertion A: Earth has atmosphere whereas moon doesn't have any atmosphere.
Reason R: The escape velocity on moon is very small as compared to that on earth.
In the light of the above statement, choose the correct answer from the options given below :
- (A)A is true but R is false
- (B)A is false but R is true
- (C)Both A and R are correct but R is NOT the correct explanation of A
- (D)Both A and R are correct and R is correct explanation of A✓ Correct
Answer: (D)
Solution
Both statements are correct, and R correctly explains A.
The Moon has a much lower escape velocity (~2.4 km/s) compared to Earth (~11.2 km/s) due to its smaller mass and radius. The rms velocity of gas molecules at the Moon's surface temperature is comparable to or exceeds the escape velocity, allowing atmospheric molecules to escape into space. This is why the Moon cannot retain an atmosphere, while Earth can. Therefore, R is the correct explanation of A.
The Moon has a much lower escape velocity (~2.4 km/s) compared to Earth (~11.2 km/s) due to its smaller mass and radius. The rms velocity of gas molecules at the Moon's surface temperature is comparable to or exceeds the escape velocity, allowing atmospheric molecules to escape into space. This is why the Moon cannot retain an atmosphere, while Earth can. Therefore, R is the correct explanation of A.
JEE Main · 2023 · 06 Apr 2023 · Shift 1 · Single correct option