Question

a 1500 watt, 120vac heater is designed with a single resistive heating element. (a) what is the value of the resistance? (b) we measure the voltage of a certain wall outlet with nothing plugged into it, and verify that it is indeed 120vac. we also measure the resistance of the heater, and it's as it should be from part (a). yet when we plug in the heater, it only draws 1150 watts. explain how this could be possible. be quantitative!

Answer 1

The value of resistance for the 1500 watt, 120VAC heater is 9.6 ohms. The heater only drawing 1150 watts instead of 1500 watts can be due to power loss or inefficiencies in the system.

Step-by-step explanation:

(a) To find the value of resistance for the 1500 watt, 120VAC heater, we can use the formula P = V^2 / R, where P is the power, V is the voltage, and R is the resistance. Rearranging the formula, we have R = V^2 / P. Substituting the values, we get R = 120^2 / 1500 = 9.6 ohms.

(b) When the heater only draws 1150 watts instead of the expected 1500 watts, it indicates that there is some power loss or inefficiency in the system. This could be due to factors such as Joule heating in the wiring, resistance in the connections, or improper calibration of measuring devices. These factors can cause a decrease in power delivered to the heater.