Two idential straight wires are stretched so as to produce `6` beats per second when vibrating simultaneously. On changing the tension slightly in one of them, the beat frequency remains unchanged. Denoting by `T_(1)`, `T_(2)` the higher and the lower initial tension in the strings, then it could be said that while making the above changes in tension,

Options

A. `T_2` was decreased
B. `T_2` was increased
C. `T_1` was increased
D. `T_1` was decreased

Answer

B, D

Explanation

`T_(1)` and `T_(2)` are the higher and lowest tensions initially.
Now, frequency `prop sqrt("tension")`.
Therefore, frequency produced in wire with tension `T_(1)` is higher and that with tension `T_(2)` is lower. If we lower the tension `T_(2)` then beat frequency will increase. Therefore, the tension `T_(1)` is decreased. If tension has to be increased then tension `T_(2)` should be increased.