Obtain the expression for the mutual inductance of two long coaxial solenoids `S_(1)` and `s_(2)` wound one over the other, each of length L and radii `r_(1) and r_(2)` and `n_(1) and n_(2)` number of turns per unit length, when a current I is set up in the outer solenoid `S_(2)`.

A solenoid with 7 turns per unit length is carrying a current of 2.5A . What is the magnetic intensity inside the solenoid ?

Two solenoids of equal number of turns have their lengths and the radii in the same ratio 1 : 2 . The ratio of their self-inductances will be

If a rate of change of current of 2 A.s^(-1) induces an emf of 10 mV in a solenoid, what is the self-inductance of the solenoid?

Two solenoids made of insulated conducting wires and of equal lengths are such that one is wound over another. Resistance of each of them is R and number of turns per unit lenghts is n. The solenoids are now conected in series and if current flows through them in the same direction in both cases, determine the magnetic field along the axis of solenoids in each case.