Question

A closely wound solenoid of 800 turns and area of cross section `2*5xx10^-4m^2` carries a current of `3*0A`. Explain the sense in which the solenoid acts like a bar magnet. What is its associated magnetic moment?

Answer 1

It is given that number of turns, N=800N
Area of cross-section, A=`2.5xx10^(4)m^(2)`
Now, magnetic moment of the solenoid is
`" " M=NIA=800xx3.0xx2.5xx10^(-4)`
`" " =0.60JT^(-1)`
Which acts along the axis of the solenoid in the direction releated to the sence of flow of current according to right handed screw rule.