Question

Set up the circuit shown in Figure again. Move the key to ‘ON’ position and watch carefully in which direction the compass needle gets deflected. Switch ‘OFF’ the current. Now keeping rest of the circuit intact, reverse the connections at the terminal of the cell. Again switch ‘on’ the current. Note the direction in which the needle gets deflected. Think of an explanation.

Answer 1

1. Set up the Circuit:
   • Connect the components as shown in the figure: battery, switch, wire wound around cardboard, and a compass.
2. Turn the Switch 'ON':
   • Close the switch to 'ON'.
   • Observe and note the direction of the compass needle deflection.
3. Turn the Switch 'OFF':
   • Open the switch to 'OFF'.
4. Reverse Battery Connections:
   • Swap the positive and negative terminals of the battery.
5. Turn the Switch 'ON' Again:
   • Close the switch to 'ON'.
   • Observe and note the direction of the compass needle deflection again.
6. Explanation:
   • The compass needle deflects due to the magnetic field created by the current.
   • Reversing the battery connections reverses the current direction, thus reversing the magnetic field and the needle's deflection direction.