Spherical insulating ball and a spherical metallic ball of same size and mass are dropped from the same height. Choose the correct statement out of the following {Assume negligible air friction}

For the given circuit, in the steady state, $\left|V_B-V_D\right|=$ _____ $\mathrm{V}$.

Match the List-I with List-II.

Choose the correct answer from the options given below:

A coil is placed in magnetic field such that plane of coil is perpendicular to the direction of magnetic field. The magnetic flux through a coil can be changed:

A. By changing the magnitude of the magnetic field within the coil.

B. By changing the area of coil within the magnetic field.

C. By changing the angle between the direction of magnetic field and the plane of the coil.

D. By reversing the magnetic field direction abruptly without changing its magnitude.

Choose the most appropriate answer from the options given below:

A square shaped coil of area $70 {\mathrm{cm}}^2$ having $600$ turns rotates in a magnetic field of $0.4 \mathrm{Wb} {\mathrm{m}}^{–2}$, about an axis which is parallel to one of the side of the coil and perpendicular to the direction of field. If the coil completes $500$ revolution in a minute, the instantaneous emf when the plane of the coil is inclined at $60°$ with the field, will be ______ $\mathrm{V}$.

(Take $\pi \mathit{=}\frac{\mathit{22}}{\mathit{7}}$)