How Much Power Does an 18Ω Toaster Use on a 220V Source?

[tDexx]

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

 

[PeterO]

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.

 

[physicsvalk]

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.

 

[tDexx]

What do you mean?

 

[physicsvalk]

Ohm's law relates the resistance, current and voltage of a circuit. Knowing this, you can solve for anyone (resistance, current, voltage) and put it in terms of the other two.