Before using the tangent galvanometer, its coil is set in
Magnetic meridian (or vertically north south)
Perpendicular to magnetic meridian
At angle of ${45^o}$ to magnetic meridian
It does not require any setting
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 needle of a deflection galvanometer shows a deflection of $60^o $ due to a short bar magnet at a certain distance in $\tan A$ position. If the distance is doubled, the deflection is
The length of a magnet is large compared to its width and breadth. The time period of its oscillation in a vibration magnetometer is $2 \,s. $ The magnet is cut along its length into three equal parts and three parts are then placed on each other with their like poles together. The time period of this combination 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........$amp$
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......$A$