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Power Consumption #2

  • Thread starter tDexx
  • Start date
  • #1
6
0

Homework Statement


A toaster with 18Ω is conducted to a 220 volt source. What is the power consumed by the toaster.


Homework Equations


P=IV


The Attempt at a Solution


P=18(220)
P= 3,960
 

Answers and Replies

  • #2
PeterO
Homework Helper
2,425
46

Homework Statement


A toaster with 18Ω is conducted to a 220 volt source. What is the power consumed by the toaster.


Homework Equations


P=IV


The Attempt at a Solution


P=18(220)
P= 3,960
You have multiplied the resistance by the voltage, the formula you stated was for current by voltage.
You need to incorporate Ohms law.
 
  • #3
Although it seems annoying, it helps to keep re-writing your units to check if your answer has the correct dimensions.

P = IV is a good equation to use, but here you aren't given the current; you're given the resistance of the toaster. Try using Ohm's law to rearrange the equation for power and find an equation whose knowns are already given.
 
  • #4
6
0
What do you mean?
 
  • #5
Ohm's law relates the resistance, current and voltage of a circuit. Knowing this, you can solve for any one (resistance, current, voltage) and put it in terms of the other two.
 

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