Three identical long solenoids P,Q and R are connected to each other as shown in figure . If the magnetic field at the centre of P is 2.0 T, what would be the field at the centre of Q? Assume that the field due to any solenoid is confined within the volume of that solenoid only.

Explanation

Solution: As the solenoids are identical, the currents in
Q and R will be same and will be half the current
in P. The magnetic field within a solenoid is given by
` B=(mu_0)ni. Hence the field in Q will be equal to the field`
in R and will be half the field in P, i.e., will be 1.0 T.