A vibration magnetometer is placed at the south pole; then its the time period will be
Zero
Infinity
Same as at magnetic equator
Same as at any other place on the earth
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
Assertion : Magnetic Resonance Imaging $(MRI)$ is a useful diagnostic tool for producing images of various parts of human body.
Reason : Protons of various tissues of the human body play a role in $(MRI)$.
Two short magnets having magnetic moments in the ratio $27 : 8,$ when placed on opposite sides of a deflection magnetometer, produce no deflection. If the distance of the weaker magnet is $0.12$ $m$ from the centre of deflection magnetometer, the distance of the stronger magnet from the centre is.......$m$
A tangent galvanometer has $80$ turns of wire. The internal and external diameters of the coil are $19 \,cm$ and $21 \,cm$ respectively. The reduction factor of the galvanometer at a place where $H=0.32$ oersted will be $(1$ oersted $=80 \,A / m )$
The magnetic needle of a tangent galvanometer is deflected at an angle $30^o$ due to a magnet. The horizontal component of the earth's magnetic field is $0.34 \times 10^{-4}\, T$ which is along the plane of the coil. The magnetic field due to magnet is