Q4. A light string passing over a smooth light pulley connects two blocks of masses $m _ { 1 }$ and $m _ { 2 }$ (where $m _ { 2 } > m _ { 1 }$ ). If the acceleration of the system is $\frac { g } { \sqrt { 2 } }$, then the ratio of the masses $\frac { m _ { 1 } } { m _ { 2 } }$ is:\\
(1) $\frac { 1 + \sqrt { 5 } } { \sqrt { 5 } - 1 }$\\
(2) $\frac { \sqrt { 2 } - 1 } { \sqrt { 2 } + 1 }$\\
(3) $\frac { 1 + \sqrt { 5 } } { \sqrt { 2 } - 1 }$\\
(4) $\frac { \sqrt { 3 } + 1 } { \sqrt { 2 } - 1 }$