In the given circuit,when does the lamp become momentarily bright?

In an $L-R$ circuit connected to a battery of constant $e.m.f.$ $E$,switch $S$ is closed at time $t = 0$. If $e$ denotes the magnitude of induced $e.m.f.$ across the inductor and $i$ the current in the circuit at any time $t$,then which of the following graphs shows the variation of $e$ with $i$?

$A$ conducting ring of radius $a$ is rotated about a point $O$ on its periphery as shown in the figure in a plane perpendicular to a uniform magnetic field $B$ which exists everywhere. The rotational velocity is $\omega$. Choose the correct statement$(s)$ related to the induced current in the ring.

An inductance of $2\,H$ carries a current of $2\,A$. To prevent sparking when the circuit is broken,a capacitor of $4\,\mu F$ is connected across the inductance. The voltage rating of the capacitor is of the order of

$A$ bar magnet falls from rest under gravity through the centre of a horizontal ring of conducting wire as shown in figure. Which of the following graph best represents the speed $(v)$ vs. time $(t)$ graph of the bar magnet?

In a coil of resistance $100 \ \Omega$,a current is induced by changing the magnetic flux through it as shown in the figure. The magnitude of change in flux through the coil is......$Wb$.