Question

How would you demonstrate that momentary current can be obtained by the suitable use of a magnet, a coil of wire and a galvanometer?

• A. By moving the magnet towards the coil connected to the galvanometer
• B. By moving the magnet away from the coil connected to the galvanometer
• C. both A & B
• D. Insufficient information

Answer 1

The correct option is C both A & B

When a magnet is moved closer to the current carrying coil it will generate electricity as the coil moves through the magnetic field. As the magnet is moved, there will be an induced electro-motive force (EMF) which can cause a current in the coil. Once the magnet stops moving, the current will go to zero.
Hence, when a galvanometer is connected to the circuit, there will be deflection due to the flow of electricity. As the magnet is moved toward the coil of wire, the needle of the galvanometer moves one direction. As the magnet is moved away from the coil of wire, the needle of the galvanometer moves the opposite direction. If the magnet is moved faster, the magnitude of the deflection increases.
If, we hold the magnet in place and move the coil of wire toward the magnet, the same thing happens.
The magnitude of the induced current and voltage is dependent on the relative motion of the coil of wire and the magnet.
The mechanical movement is converted into electrical energy.