The radius of the coil of a Tangent galvanometer. which has $ 10 $ $turns$ is $0.1\,m. $ The current required to produce a deflection of $60°$  $({B_H} = 4 \times {10^{ - 5}}\,T)$ is.....$A$

A vibration magnetometer consists of two identical bar magnets placed one over the other such that they are mutually perpendicular and bisect each other. The time period of oscillation in a horizontal magnetic field is $4\, sec$. If one of the magnets is taken away, find the period of oscillation of the other in the same field (in $sec.$) :-

The bob of a simple pendulum is replaced by a magnet. The oscillations are set along the length of the magnet. A copper coil is added so that one pole of the magnet passes in and out of the coil. The coil is short-circuited. Then which one of the following happens

A tangent galvanometer shows a deflection $45^o $ when $10\, mA$ current pass through it. If the horizontal component of the earth’s field is $3.6 \times {10^{ - 5}}\,T$ and radius of the coil is $10\, cm$. The number of turns in the coil is......$turns$

Tangent galvanometer is used to measure

A long vertical wire in which a current is flowing produces a neutral point with the earth's magnetic field at a distance of $5\, cm$ from the wire. If the horizontal component of the earth's magnetic induction is $0.18\, gauss$, then the curent in the wire is......$A$