A heating element is marked 210 V, 630 W. The current drawn by the element and the resistance of the element when connected to 210 V DC mains would respectively be:

$3 A, 70 \Omega$

The correct answer is Option (2) → $3 A, 70 \Omega$

Given,

V, Voltage of the heating element = 210 V

P, Power of the heating element = 630 W

Also,

$P=V×I$ [formula]

where,

I, current in the circuit

∴ $I=\frac{P}{V}=\frac{630}{210}$

$I=3A$

Now,

$P=V.\frac{V}{R}$ [V = IR : Ohm's law]

$⇒R=\frac{V^2}{P}=\frac{(210)^2}{630}$

$=70Ω$