Q10 of 238 Page 81

State three ways in which the strength of an electromagnet can be increased.

The three ways are :-

(1) By increasing the number of turns in the coil.

(2) Increase the current flow in the coil.

(3) The air gaps between the poles should must be reduced.

State whether the following statement is true or false:

The magnetic field inside a long circular coil carrying current will be parallel straight lines.

What is the shape of current-carrying conductor whose magnetic field pattern resembles that of a bar magnet?

Fill in the following blanks with suitable words:

(a) The lines of _____ round a straight-carrying conductor are in the shape of _____

(b) For a current-carrying solenoid, the magnetic field is like that of a _____

(d) The magnetic effect of a coil can be increased by increasing the number of _____, increasing the _____ or inserting an _____ core.

(e) If a coil is viewed from one end and the current flows in an anticlockwise direction, then this end is a _____ pole.

(f) If a coil is viewed from one end, and the current flows in a clockwise direction, then this end is a _____ pole.

Describe how you will locate a current-carrying wire concealed in a wall.