In a coil of area $10 \; cm^2$ and $10$ turns, a magnetic field is directed perpendicular to the plane and is changing at the rate of $10^8 \; G/s$. The resistance of the coil is $20 \; \Omega$. The current in the coil will be ......... $A$.

$A$ coil with an area of $500 \ cm^2$ and $1000$ turns is placed in a magnetic field of $2 \times 10^{-5} \ Wb/m^2$ perpendicular to its plane. If the coil is rotated by $180^o$ in $0.2 \ s$,the induced $emf$ in $milli-volts$ is:

$A$ coil of resistance $16 \Omega$ is placed with its plane perpendicular to a uniform magnetic field whose flux ($\phi$ in $10^{-3} \text{ Wb}$) changes with time ($t$ in seconds) as $\phi = 5t^2 + 4t + 2$. The induced current at time $t = 6 \text{ s}$ is: (in $\text{ mA}$)

It is desired to measure the magnitude of the magnetic field between the poles of a powerful loudspeaker magnet. $A$ small flat search coil of area $2 \; cm^{2}$ with $25$ closely wound turns is positioned normal to the field direction and then quickly snatched out of the field region. (Equivalently,one can give it a quick $90^{\circ}$ turn to bring its plane parallel to the field direction). The total charge flown in the coil (measured by a ballistic galvanometer connected to the coil) is $7.5 \; mC$. The combined resistance of the coil and the galvanometer is $0.50 \; \Omega$. Estimate the field strength of the magnet.

The magnetic flux linked with a coil,in weber,is given by the equation $\phi = 5t^2 + 3t + 16$. The induced emf in the coil in the fourth second is.....$V$

$A$ coil has $1,000$ turns and $500 \, cm^2$ as its area. The plane of the coil is placed at right angles to a magnetic induction field of $2 \times 10^{-5} \, Wb/m^2$. The coil is rotated through $180^o$ in $0.2 \, s$. The average $e.m.f.$ induced in the coil,in milli-volts,is