Define the term 'mutual inductance' between the two coils.
Obtain the expression for mutual inductance of a pair of long coaxial solenoids each of I and radii `r_(1) and `r_(2)(r_(2)gt gt r_(1))`. Total number of solenoids are `N_(1) and N_(2)` respectively.

Obtain an expression for the self inductance of a straight solenoid of length l and radius r (l > > r).

The capacitance of two concentric spherical shells of radii R_(1) and R_(2) (R_(2) gt R_(1)) is

Define mutual inductance between two long coaxial solenoids. Find out the expression for the mutual of inner solenoid of length 1 having the radius r_(1) and the number of turns n_(1) per unit length due to the second other solenoid of same length and n_(2) number of turns per unit length.

Find the mutual inductance of two concentric coils of radii a_(1) and a_(2)(a_(1) lt lt a_(2)) if the planes of the coils are same.

Define self -inductance and its S.I. unit. Derive an expression for self- industance of a long, air-cored solenoid of length , radius r , and having N number of turns.

When two soap bubbles of radius r_(1) and r_(2)(r_(2) gt r_(1)) coalesce, the radius of curvature of common surface is