A closely wound solenoid of 800 turns and area of cross section 2.5 \times 10 ^{-4} m^2 carries a current of 3.0 A. Explain the sense in which the solenoid acts like a bar magnet. What is its associated magnetic moment?

Answers (1)

In this case the magnetic field is generated along the axis / length of solenoid so it acts as a magnetic bar.

 The magnetic moment is calculated as :- 

                                        M\ =\ NIA

or                                             =\ 800\times 3\times 2.5\times 10^{-4}

or                                              =\ 0.6\ JT^{-1}