$A$ coil of surface area $200 \ cm^2$ having $25$ turns is held perpendicular to the magnetic field of intensity $0.02 \ Wb/m^2$. The resistance of the coil is $1 \ \Omega$. If it is removed from the magnetic field in $1 \ s$,the induced charge in the coil is . . . . . . $C$.

If a coil of $40$ turns and area $4.0 \, cm^2$ is suddenly removed from a magnetic field,it is observed that a charge of $2.0 \times 10^{-4} \, C$ flows through the coil. If the resistance of the coil is $80 \, \Omega$,the magnetic flux density in $Wb/m^2$ is:

$A$ rectangular loop of length $2.5 \ m$ and width $2 \ m$ is placed at $60^{\circ}$ to a magnetic field of $4 \ T$. The loop is removed from the field in $10 \ s$. The average emf induced in the loop during this time is

$A$ $10 \Omega$ coil of $180$ turns and diameter $4 \text{ cm}$ is placed in a uniform magnetic field so that the magnetic flux is maximum through the coil's cross-sectional area. When the field is suddenly removed, a charge of $360 \mu \text{C}$ flows through a $618 \Omega$ galvanometer connected to the coil. Find the magnetic field. (in $\text{ T}$)

There are two square loops $A$ and $B$. When $A$ moves towards $B$,a current starts flowing in $B$ as shown in the figure,and the current in $B$ stops when $A$ stops moving. From this,we can infer that (Assume loop $B$ is at rest):

$A$ flexible wire loop in the shape of a circle has a radius that grows linearly with time. There is a magnetic field perpendicular to the plane of the loop that has a magnitude inversely proportional to the distance from the center of the loop,i.e.,$B(r) \propto \frac{1}{r}$. How does the emf $E$ vary with time?