JEE Main 2019 Physics question

A rod of mass 'M' and length '2L' is suspended at its middle by a wire. It exhibits torsional oscillations; If two masses each of 'm' are attached at distance 'L/2' from its centre on both sides, it reduces the oscillation frequency by 20%. The value of ratio m/M is close to:

• (A)0.37Correct
• (B)0.57
• (C)0.77
• (D)0.17