Question

An electric heater with a power of 900 W has a resistance of 36 Ω. Calculate the magnitude of the current and the p.d. at its ends.

Answer 1

P = 900 W; R = 36 Ω; I = ?; V = ?

\[I = \sqrt{\frac{P}{R}}\]

\[= \sqrt{\frac{900}{36}}\]

\[= \sqrt{25}\]

= 5.0 A

V = I × R

= 5.0 × 36

= 180 V