Magnetic Effects of Electric Current

 A compass needle is a small magnet. Its one end, which points towards north, is called a north pole, and the other end, which points towards south, is called a south pole.

 An electromagnet consists of a core of soft iron wrapped around with a coil of insulated copper wire

 A generator converts mechanical energy into electrical energy. It works on the basis of electromagnetic induction

 In our houses we receive AC electric power of 220 V with a frequency of 50 Hz.

 One of the wires in this supply is with red insulation, called live wire.

 The other one is of black insulation, which is a neutral wire. The potential difference between the two is 220 V.

 The third is the earth wire that has green insulation and this is connected to a metallic body deep inside earth. It is used as a safety measure to ensure that any leakage of current to a metallic body does not give any severe shock to a user.

FUSE

 A fuse in a circuit prevents damage to the appliances and the circuit due to overloading. Overloading can occur when the live wire and the neutral wire come into direct contact.

 (This occurs when the insulation of wires is damaged or there is a fault in the appliance.)

 In such a situation, the current in the circuit abruptly increases. This is called short-circuiting. The use of an electric fuse prevents the electric circuit and the appliance from a possible damage by stopping the flow of unduly high electric current.

 The heating that takes place in the fuse melts it to break the electric circuit.

 Overloading can also occur due to an accidental hike in the supply voltage. Sometimes overloading is caused by connecting too many appliances to a single socket.