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

AI Thread Summary
To determine the power consumed by an 18Ω toaster connected to a 220V source, the correct approach involves using Ohm's law. The initial calculation incorrectly multiplies resistance by voltage, rather than using the appropriate formula for power. The correct formula for power is P = V²/R, which incorporates the known voltage and resistance. By applying this formula, the power can be accurately calculated. Understanding and applying Ohm's law is essential for solving such electrical problems effectively.
tDexx
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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
 
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tDexx said:

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.
 
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.
 
What do you mean?
 
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.
 

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