Question

(a) What is a solenoid? Draw a sketch to show the magnetic field pattern produced by a current-carrying solenoid.
(b) Name the type of magnet with which the magnetic field pattern of a current-carrying solenoid resembles.
(c) What is the shape of field lines inside a current-carrying solenoid? What does the pattern of field lines inside a current-carrying solenoid indicate?
(d) List three ways in which the magnetic field strength of a current-carrying solenoid can be increased?
(e) What type of core should be put inside a current-carrying solenoid to make an electromagnet?

Answer 1

(a) Solenoid:
A solenoid is a long coil that contains large number of close turns of insulated copper wire.
The magnetic field pattern produced by a current-carrying solenoid is similar to the magnetic field produced by a bar magnet.


(b) The magnetic field pattern of a current-carrying solenoid resembles with that of a bar magnet.

(c) The magnetic field lines inside a solenoid are in the form of parallel straight lines. This pattern of field lines indicates that the strength of magnetic field is same at all points inside the solenoid.

(d) Ways to increase the magnetic field strength of a current-carrying solenoid:
1. By increasing the number of turns in the solenoid
2. By increasing the flow of current passing through the solenoid
3. By using a soft iron rod as core in the solenoid

(e) A soft iron rod should be put inside a current-carrying solenoid to make an electromagnet.