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 an area $2\,m^2$ is placed in a magnetic field which changes from $1\,Wb/m^2$ to $4\,Wb/m^2$ in an interval of $2$ seconds. The $e.m.f.$ induced in the coil will be......$V$.

The diagram below shows two circular loops of wire ($A$ and $B$) centred on and perpendicular to the $X$-axis and oriented with their planes parallel to each other. The $Y$-axis passes vertically through loop $A$ (dashed line). There is a current $I_B$ in loop $B$ as shown in the diagram. Possible actions which we might perform on loop $A$ are:
$(I)$ move $A$ to the right along $X$-axis closer to $B$
$(II)$ move $A$ to the left along $X$-axis away from $B$
$(III)$ as viewed from above,rotate $A$ clockwise about $Y$-axis
$(IV)$ as viewed from above,rotate $A$ anti-clockwise about $Y$-axis
Which of the actions will induce a current in $A$ only in the direction shown?

$A$ coil of $n$ turns and resistance $R \text{ } \Omega$ is connected in series with a resistance $R/4$. The combination is moved for time $t$ second through flux $\phi_1$ to $\phi_2$. The induced current in the circuit is

An electron moves on a straight line path $XY$ as shown. The $abcd$ is a coil adjacent to the path of the electron. What will be the direction of current,if any,induced in the coil?

An aluminium ring $B$ faces an electromagnet $A$. The current $I$ through $A$ can be altered. Which of the following statements is correct?