The voltage and an electric heater

In summary, the conversation discusses a 660W heater that can operate on 120V, and calculates the current and resistance needed in this situation. It also calculates the new power consumption when the voltage decreases to 110V, using two different methods. However, it is noted that the supposed answer of 500W is incorrect and the correct answer is 550W.
  • #1
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Homework Statement


A 660[W] heater can work on 120[V]. if the voltage decreases to 110[V] what is the power that it consumes?

Homework Equations


$$V=iR$$
$$P=iV$$
For pure resistance: ##P=i^2R##

The Attempt at a Solution


The current at 660[W]: ##P=i\cdot 120\rightarrow i=5.5[A]##
The resistance: ##660=5.5^2\cdot R\rightarrow R=22[\Omega]##
The new current: ##V=iR\rightarrow 110=i\cdot 22\rightarrow i=5[A]##
The new power consumption: ##P=i\cdot V=5\cdot 110=550[W]##
And with another method: ##P=i^2\cdot R=5^2\cdot 22=550[W]##
It is written that it should be 500[W]
 
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  • #2
Your calculations look fine. The supposed answer is not correct.
 
  • #3
Thanks, gneil
 
  • #4
My guess is the rated power should be given as 600W, not 660W.
 
  • #5
Thank you too, haruspex, but the other partial answers to this question, which i didn't fully copy here, fit 660[W], but i guess this problem is solved
 

1. What is the relationship between voltage and an electric heater?

The voltage and an electric heater have a direct relationship. An increase in voltage will result in an increase in the amount of heat produced by the heater. This is because a higher voltage allows more electrical current to flow through the heater, generating more heat.

2. How does the voltage affect the temperature of an electric heater?

The voltage directly affects the temperature of an electric heater. The higher the voltage, the hotter the heater will become. This is why it is important to use the correct voltage for your heater, as a higher voltage can cause it to overheat and potentially become a fire hazard.

3. Can the voltage of an electric heater be adjusted?

Yes, the voltage of an electric heater can be adjusted. Some heaters have a built-in voltage control, while others may require an external voltage regulator. It is important to follow the manufacturer's instructions when adjusting the voltage to ensure safe operation of the heater.

4. What happens if the voltage of an electric heater is too high?

If the voltage of an electric heater is too high, it can cause the heater to overheat and potentially become a fire hazard. It can also shorten the lifespan of the heater and reduce its efficiency. It is important to always use the correct voltage for your heater to ensure safe and proper operation.

5. How does the voltage affect the cost of using an electric heater?

The voltage does not directly affect the cost of using an electric heater. However, using a higher voltage can result in higher energy consumption, leading to higher electricity bills. It is important to consider the voltage and energy efficiency of a heater when purchasing to help reduce long-term costs.

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