Question

What is the resistance of a bulb of 40w connected in a line of 70v​

Answer 1

Answer:

122.5 ohm

Explanation:

Given :

P=40 w

V= 70 V

R=?

Resistance can be calculated as :

$P=\frac{V^{2} }{R} \\40=\frac{(70)^{2} }{R}\\40=\frac{4900}{R} \\R=\frac{4900}{40} \\R=122.5 ohm$

Therefore, resistance of the bulb will be 122.5 ohm