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

Activity 13.7

Take a small aluminium rod AB (of about 5 cm). Using two connecting wires suspend it horizontally from a stand, as shown in Fig. 13.12.

 Fig. 13.12

Place a strong horse-shoe magnet in such a way that the rod lies between the two poles with the magnetic field directed upwards. For this put the north pole of the magnet vertically below and south pole vertically above the aluminium rod (Fig. 13.12).

Connect the aluminium rod in series with a battery, a key and a rheostat.

Now pass a current through the aluminium rod from end B to end A.

What do you observe? It is observed that the rod is displaced towards the left. You will notice that the rod gets displaced.

Reverse the direction of current flowing through the rod and observe the direction of its displacement. It is now towards the right. Why does the rod get displaced?

✅ Answer: The displacement of the rod (AB) suggests that
• A force is exerted on the current-carrying aluminium rod when it is placed in a magnetic field.
• The direction of force is also reversed when the direction of current through the conductor is reversed.