When a conducting wire $XY$ is moved towards the right,a current flows in the anti-clockwise direction in the loop. The direction of the magnetic field at point $O$ is

$A$ circular coil of area $100 \,cm^2$ and $20$ turns is kept in a magnetic field of flux density $2 \,Wb/m^2$. It rotates from a position where its plane makes an angle of $30^{\circ}$ with the field to a position perpendicular to the field in a time $0.2 \,s$. Find the magnitude of the emf induced in the coil due to its rotation. (in $V$)

Assertion $(A)$: It is more difficult to push a magnet into a coil with a greater number of turns.
Reason $(R)$: The $emf$ induced in a coil opposes the motion of a magnet when it is moved towards the coil.

An insulated copper wire of $100$ turns is wrapped around a wooden cylindrical core of the cross-sectional area $24\,cm^2$. The two ends of the wire are connected to a resistor. The total resistance in the circuit is $12\,\Omega$. If an externally applied uniform magnetic field in the core along its axis changes from $1.5\,T$ in one direction to $1.5\,T$ in the opposite direction,the charge flowing through a point in the circuit during the change of magnetic field will be $.........\,mC$.

The north pole of a long horizontal bar magnet is being brought closer to a vertical conducting plane along the perpendicular direction. The direction of the induced current in the conducting plane will be

The magnetic flux through a coil of resistance $10\,\Omega$ changes. As a result,an induced current is developed in it,which varies with time as shown in the figure. The magnitude of the change in magnetic flux through the coil in webers is: