Q 11-07-144JEE MainJEE Main 2021 (25 Feb, Shift 1)Easy
Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
**Assertion A:** The escape velocities of planet $A$ and $B$ are same. But $A$ and $B$ are of unequal mass.
**Reason R:** The product of their mass and radius must be same. $M_1R_1 = M_2R_2$.
In the light of the above statements, choose the most appropriate answer from the options given below:
Answer: (D) $A$ is correct but $R$ is not correct
$v_e = \sqrt{\dfrac{2GM}{R}}$. Two planets of unequal mass can have the same escape velocity if $\dfrac{M_1}{R_1} = \dfrac{M_2}{R_2}$, so A is correct.
The condition is equal $M/R$, not equal $MR$, so R is not correct.
Solution by Sreeraj P, M.Sc Physics