Question

A resistor uses 100 w of power when connected to 120 v emf. What is the current through the same resistor when connected to a 220 v emf?

Answer 1

Step-by-step explanation:

Let the resistance of resistor be R .

Power of resistor V² / R , where V is potential applied .

V² / R = 100

120² / R = 100

R = 120² / 100

= 144 ohm .

Now potential diff applied = 220 V

current = potential diff / resistance

= 220 / 144

= 1.53 A approx .