The protection system of the household circuit that trips if someone receives a shock is:

Question

Question

This question was previously asked in

ALP CBT 2 Electrician Previous Paper: Held on 22 Jan 2019 Shift 2

Answer 1

The sensation of electric shock is caused by the flow of electric current through the human body to the earth.
When a person comes in contact with electrically live objects like water heaters, washing machines electric iron, etc., the extent of damages caused by this current depends on its magnitude and duration.
This kind of current is called the leakage current which comes in milli-amps.
These leakage currents being very small in magnitude, hence undetected by the fuses/MCBs are the major cause for the fires due to electricity.
Residual current operated circuit breakers provide maximum protection from electric shocks and fires caused due to earth leakage current and also prevents the waste of electrical energy.
These residual current circuit breakers (RCCB) are popularly called as earth leakage circuit breakers (ELCB).