Question

An MCB which cuts off the electricity supply in case of short-circuiting works on the ______.

Options

• chemical effect of current.

• charging effect of current.

• magnetic effect of current.

• electroplating effect of current.

Answer 1

An MCB which cuts off the electricity supply in case of short-circuiting works on the magnetic effect of current.

Explanation:

An MCB contains a built-in electromagnet (solenoid) that responds to abnormal current flows. In the event of a severe fault like a short-circuit, the massive surge in current instantly creates a powerful magnetic field within the electromagnet. This magnetic force rapidly pulls an internal plunger to trip the mechanical latch, breaking the circuit instantly to prevent fire or appliance damage.