$A$ copper rod is moved in a magnetic field. The charge developed across its ends will be proportional to

$A$ coil of resistance $8 \Omega$,number of turns $250$,and area $120 \ cm^2$ is placed in a uniform magnetic field of $2 \ T$ such that the plane of the coil makes an angle of $\frac{\pi}{6}$ with the direction of the magnetic field. In a time of $100 \ ms$,the coil is rotated until its plane becomes parallel to the direction of the magnetic field. The current induced in the coil is (in $A$)

$A$ cylindrical bar magnet is kept along the axis of a circular coil. If the magnet is rotated about its axis,then

Two identical circular loops of metal wire are lying on a table without touching each other. Loop $A$ carries a current which increases with time. In response,the loop $B$:

$A$ conducting loop is placed in a uniform magnetic field with its plane perpendicular to the field. An $emf$ is induced in the loop if:
$(a)$ It is translated (inside the field)
$(b)$ It is rotated about its axis
$(c)$ It is rotated about a diameter
$(d)$ It is deformed

$A$ magnetic field $B$ is confined to a region $r \le a$ and points out of the paper (the $z$-axis),$r = 0$ being the centre of the circular region. $A$ charged ring (charge $= Q$) of radius $b$,$b > a$ and mass $m$ lies in the $xy$-plane with its centre at the origin. The ring is free to rotate and is at rest. The magnetic field is brought to zero in time $\Delta t$. Find the angular velocity $\omega$ of the ring after the field vanishes.