Two tangent galvanometer coils of same radius connected in series. The current flowing produces deflection of $60^o$ and $45^o$. The ratio of number of turns in coil is

The sensitivity of a tangent galvanometer is increased if

Two magnets are held together in a vibration magnetometer and are allowed to oscillate in the earth’s magnetic field. With like poles of magnets together, $12\, oscillations$ per minute are made but for unlike poles together only $4\, oscillations$ per minute are executed. The ratio of their magnetic moments is

If a brass bar is placed on a vibrating magnet, then its time period

At two places $ A $ and $B$  using vibration magnetometer, a magnet vibrates in a horizontal plane and its respective periodic time are $2$ $sec$ and $3$ $sec$ and at these places the earth's horizontal components are $H_A$ and $H_B$ respectively. Then the ratio between $H_A$ and $H_B$ will be

When $2 $ $amperes$ current is passed through a tangent galvanometer, it gives a deflection of $30^o$. For $60^o$ deflection, the current must be........$amp$