A long, closely wound solenoid carries an electric current. A student is asked to…
PHYSICS · Multi-part · CBSE · Physics · Magnetic Effects of Electric Current · Magnetic Effects of Electric Current
Problem
A long, closely wound solenoid carries an electric current. A student is asked to analyse the magnetic field associated with this solenoid using only the qualitative properties of magnetic field lines.
(i) Draw a clear diagram to show the magnetic field pattern inside and outside the solenoid.
(ii) Using the origin–termination rule and the idea of line density, explain why the magnetic field inside the solenoid is almost uniform and much stronger than the field outside.
(iii) Reason out qualitatively why the magnetic field inside the solenoid depends on the number of turns per unit length and the current in the wire, but is nearly independent of the solenoid’s diameter.