The diagram illustrates a coil of wire positioned between the poles of a magnet. The coil is made of 20 turns of insulated wire and is linked to a variable resistor and a power supply. How can the turning effect on the coil be increased?
- Aby moving the poles of the magnet closer to the coil
- Bby reducing the number of turns on the coil while keeping the current constant
- Cby increasing the resistance of the variable resistor
- Dby reversing the terminals of the power supply