The variation of induced emf $(E)$ with time $(t)$ in a coil if a short bar magnet is moved along its axis with a constant velocity is best represented as

An electron is moving in a circular orbit of radius $R$ with an angular acceleration $\alpha$. At the centre of the orbit is kept a conducting loop of radius $r$ $(r \ll R)$. The $e.m.f.$ induced in the smaller loop due to the motion of the electron is

$A$ short magnet is allowed to fall along the axis of a horizontal metallic ring. Starting from rest,the distance fallen by the magnet in one second may be.....$m$

The current $(I)$ in the inductance is varying with time according to the plot shown in the figure. Which one of the following is the correct variation of voltage $(V)$ with time in the coil?

$(a)$ $A$ closed loop is held stationary in the magnetic field between the north and south poles of two permanent magnets held fixed. Can we hope to generate current in the loop by using very strong magnets?
$(b)$ $A$ closed loop moves normal to the constant electric field between the plates of a large capacitor. Is a current induced in the loop
$\quad (i)$ when it is wholly inside the region between the capacitor plates
$\quad (ii)$ when it is partially outside the plates of the capacitor? The electric field is normal to the plane of the loop.
$(c)$ $A$ rectangular loop and a circular loop are moving out of a uniform magnetic field region to a field-free region with a constant velocity $v$. In which loop do you expect the induced emf to be constant during the passage out of the field region? The field is normal to the loops.
$(d)$ Predict the polarity of the capacitor in the situation described by the figure.

The current $i$ in an induction coil varies with time $t$ according to the graph shown in the figure. Which of the following graphs shows the induced emf $(E)$ in the coil with time?