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Ravindran got an electric shock when he touched the heating coil of an electric heater, although the switch was in 'off' position. What could have been the reason?

Ravindran got an electric shock when he touched the heating coil of an electric heater, although the switch was in 'off' position. What could have been the reason? Correct Answer The switch was connected to the neutral wire

CONCEPT:

  • The device which uses electricity to do a function is called as electrical appliances.
    • For example electric iron, water heater, or room heater.

There are three types of wires in connecting cables:

Live wire Neutral wire Earth wire
The wire which carries electric current to the appliances is called a live wire. The wire which completes the circuit by forming a way to current back to the mains is called Neutral wire. 
The neutral wire is at zero volts generally.		 The wire of very low resistance which is generally connected to the earth is called earth wire.
EXPLANATION:
  • The domestic supply has one of the three-phase wires and a neutral wire.
  • This electric supply is connected with the reference to an earthed wire.
  • The neutral wire in the supply is common for all three phases.
  • When the switch is connected to an electric heater, it can be connected with the phase or neutral wire to make the heater on or off.
  • If the switch is connected with the neutral wire, the phase line that connects with the electric heater is always connected.
  • That's why even the switch is off Ravindran can get an electric shock when he touched the heating coil. So option 3 is correct.

NOTE:

  • When the switch is connected with the phase wire, then we will get shocked when it is on only. With the switch is in off, we will not get shocked.

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