Power Rating of 570 W Heaters in Series: 1140 W

[GreenDinos]

Q20-9. The power rating of a 570 W heater specifies the power consumed when the heater is connected to an ac voltage of 120V. What is the power consumed by two of these heaters connected in series, connected to the same voltage?

570 W
285 W
1140 W
2280 W
142.5 W

ok, my original thinking was that the 120V will supply 570 W of power and that two in a series would still have a total power of 570W (285W each)...but that was wrong...so is it double the power (1140W)- is the power consumed still 570W for each heater- and so 1140 is the total?

thanks

 

[chroot]

Power is voltage times current. Ohm's law says voltage is current times resistance.

$$P = V \cdot I = \frac{V^2}{R}$$

Solving for resistance:

$$R = \frac{V^2}{P}$$

Replacing R with 2R:

$$P_{\textrm{both}} = \frac{V^2 \cdot P}{2 V^2} = \frac{P}{2}$$

- Warren

 

[M98Ranger]

for your response!

In this scenario, when two 570 W heaters are connected in series, the total power consumed would be 1140 W. This is because when heaters are connected in series, the voltage remains the same, but the current is divided between the two heaters. So each heater would still consume 570 W, but together they would consume a total of 1140 W. This is because power is calculated by multiplying voltage by current, and in this case, the voltage remains constant at 120V for both heaters. Therefore, the power consumed by two 570 W heaters connected in series would be 1140 W.