Question

A heater coil rated as (P, V) is cut into two equal parts. One of the parts is then connected to a battery of V volt. The power consumed by it will be ______.

Options

• P

• `P/2`

• `P/4`

• 2P

Answer 1

A heater coil rated as (P, V) is cut into two equal parts. One of the parts is then connected to a battery of V volt. The power consumed by it will be 2P.

Explanation:

Resistance of coil `R = rhol/A`

R ∝ l

Heater coil cut into two parts, i.e., `l = l/2`

`R = R/2`

Power = `V^2/R = V^2/(R/2)`

= `(2V^2)/R`

= 2P