The error in measuring the current with a tangent galvanometer is minimum when the deflection is about.....$^o$
$0$
$30$
$45$
$60$
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
Time period in vibration magnetometer will be infinity at
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
Which of the following statement is not the true
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