Final answer:
To calculate the current in a heating element when the voltage supply is reduced from 240 V to 120 V, first determine the resistance using the original power and voltage, then use Ohm's Law to find the new current. The resistance is calculated to be 30 ohms, leading to a current of 4 amps when connected to 120 V.
Step-by-step explanation:
The question involves calculating the current in a heating element of a stove when the voltage supply is changed. The original setup of the element is designed for 1,920 watts at 240 volts. Using Ohm's Law, we first calculate the resistance of the heating element with the original voltage and power values. Once the resistance is found, we can then calculate the new current when the element is connected to 120 volts.
Given Power (P) at 240 V = 1,920 W
Using the formula P = V2/R, where P is power, V is voltage, and R is resistance,
R = V2/P = (240 V)2 / 1,920 W = 30 ohms.
Now, we calculate the current (I) when the element is connected to 120 V.
Using Ohm's Law, I = V/R,
I = 120 V / 30 ohms = 4 amps.