The magnetic flux linked with a coil is given by the equation $\phi$ (in webers) = $8t^2 + 3t + 5$. The induced $e.m.f.$ in the coil at the $4^{th}$ second will be.......$units$.

The flux linked with a coil at any instant $t$ is given by $\phi = 10t^2 - 50t + 250$. The induced $emf$ at $t = 3 \ s$ is ....... $V$.

$A$ coil having $200$ turns has a surface area of $0.15 \ m^2$. $A$ magnetic field of strength $0.2 \ T$ applied perpendicular to this changes to $0.6 \ T$ in $0.4 \ s$,then the induced emf in the coil is . . . . . . $V$.

Consider the experiment shown in the figure.
$(a)$ What would you do to obtain a large deflection of the galvanometer?
$(b)$ How would you demonstrate the presence of an induced current in the absence of a galvanometer?

$A$ coil having $n$ turns and resistance $R$ is connected with a galvanometer of resistance $2R$. This combination is moved in time $t$ from flux $\phi_1$ to $\phi_2 \ Wb$. The induced current in the circuit is

$A$ coil of $n$ turns and resistance $R \ \Omega$ is connected in series with a resistance $R/2$. The combination is moved for time $t$ seconds through a magnetic flux change from $\Phi_1$ to $\Phi_2$. The induced current in the circuit is: