How can you verify that a current carrying wire produces a magnetic field with the help of an experiment?

Explanation

Experiment:
1) Take a thermocol sheet and fix two thin wooden sticks of height 1 cm which have small slit at the top of their ends.
2) Arrange a copper wire of 24 gauge so that it passes through these slits and make a circuit.
3) This circuit consists of a 3 or 9V battery, key and copper wire which are connected in series as shown in the figure.
4) Now, keep a magnetic compass below the wire bring a bar magnet close to the compass.
5) The needle in the compass deflects . This deflection is due to magnetic field produced by bar magnet.
6) Take the bar magnet far away from the circuit and switch on the circuit, Observe the changes in compass.
7) The compass needle deflects.
8) This deflection is due to the magnetic field produced by current carrying wire.