# Magnetic Effects of Electric Current | Activities in Text Book with Solution

Activity 13.3

Take a small compass and a bar magnet.

Place the magnet on a sheet of white paper fixed on a drawing board, using some adhesive material.

Mark the boundary of the magnet.

Place the compass near the north pole of the magnet. How does it behave? The south pole of the needle points towards the north pole of the magnet. The north pole of the compass is directed away from the north pole of the magnet.

Mark the position of two ends of the needle.

Now move the needle to a new position such that its south pole occupies the position previously occupied by its north pole.

In this way, proceed step by step till you reach the south pole of the magnet as shown in Fig. 13.3.

 Fig. 13.3

Join the points marked on the paper by a smooth curve. This curve represents a field line.

Repeat the above procedure and draw as many lines as you can. You will get a pattern shown in Fig. 13.4. These lines represent the magnetic field around the magnet. These are known as magnetic field lines.

 Fig. 13.4

Observe the deflection in the compass needle as you move it along a field line. The deflection increases as the needle is moved towards the poles.

✅ Answer: This activity should be done by the students.