The magnetic flux (in weber) in a closed circuit of resistance $20 \ \Omega$ varies with time $t$ (in seconds) according to the equation $\phi = 5t^2 - 6t + 9$. The magnitude of the induced current at $t = 0.2 \ s$ is: (in $A$)

Use Lenz's law to determine the direction of induced current in the situations described by Figure:
$(a)$ $A$ wire of irregular shape turning into a circular shape;
$(b)$ $A$ circular loop being deformed into a narrow straight wire.

$A$ metallic ring is dropped down, keeping its plane perpendicular to a constant and horizontal magnetic field. The ring enters the region of magnetic field at $t = 0$ and completely emerges out at $t = T \, \text{sec}$. The current in the ring varies as

$A$ system $S$ consists of two coils $A$ and $B$. The coil $A$ carries a steady current $I$. The coil $B$ is suspended nearby as shown in the figure. If the system is heated,so as to raise the temperature of the two coils steadily,then:

The magnetic flux through a coil perpendicular to its plane is varying according to the relation $\phi = (5t^3 + 4t^2 + 2t - 5) \; Wb$. If the resistance of the coil is $5 \; \Omega$,then the induced current through the coil at $t = 2 \; s$ will be $.... \; A$. (in $.6$)

The induced $emf$ can be produced in a coil by:
$A.$ Moving the coil with uniform speed inside a magnetic field.
$B.$ Moving the coil with non-uniform speed inside a uniform magnetic field.
$C.$ Rotating the coil inside a uniform magnetic field.
$D.$ Changing the area of the coil inside a uniform magnetic field.
Choose the correct answer from the options given below: