Problem 5: A 10 watt resistor has a value of 120 Ω. What is rated current through the resistor?

Solution

Quite easy. The resistance of the resistor and its power is given. Maximum current (rated current is the maximum allowed current) is to be found.

Given                    Power = P = 10 watt                        Resistance = R = 120                   

Required              Current = I =?

Power is defined as P = VI = I²R

Put the values