Q7. Two planets $A$ and $B$ having masses $m _ { 1 }$ and $m _ { 2 }$ move around the sun in circular orbits of $r _ { 1 }$ and $r _ { 2 }$ radii respectively. If angular momentum of $A$ is $L$ and that of $B$ is 3 L , the ratio of time period $\left( \frac { T _ { A } } { T _ { B } } \right)$ is: (1) $\left( \frac { r _ { 2 } } { r _ { 1 } } \right) ^ { \frac { 3 } { 2 } }$ (2) $\frac { 1 } { 27 } \left( \frac { m _ { 2 } } { m _ { 1 } } \right) ^ { 3 }$ (3) $27 \left( \frac { m _ { 1 } } { m _ { 2 } } \right) ^ { 3 }$ (4) $\left( \frac { r _ { 1 } } { r _ { 2 } } \right) ^ { 3 }$
Q7. Two planets $A$ and $B$ having masses $m _ { 1 }$ and $m _ { 2 }$ move around the sun in circular orbits of $r _ { 1 }$ and $r _ { 2 }$ radii respectively. If angular momentum of $A$ is $L$ and that of $B$ is 3 L , the ratio of time period $\left( \frac { T _ { A } } { T _ { B } } \right)$ is:\\
(1) $\left( \frac { r _ { 2 } } { r _ { 1 } } \right) ^ { \frac { 3 } { 2 } }$\\
(2) $\frac { 1 } { 27 } \left( \frac { m _ { 2 } } { m _ { 1 } } \right) ^ { 3 }$\\
(3) $27 \left( \frac { m _ { 1 } } { m _ { 2 } } \right) ^ { 3 }$\\
(4) $\left( \frac { r _ { 1 } } { r _ { 2 } } \right) ^ { 3 }$