Physics Review Question

Unit: electricity
Year: 1988 Question#: 33
Question: If the power developed in an electric circuit is doubled, the energy used in one second is

(1 ) halved
(2 ) doubled
(3 ) quartered
(4 ) quadrupled

What is this question really asking?




Explanation by: Jill S

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Answer 1
halved

INCORRECT
To find out what happened to the energy if the power doubled you have to use the equation P=W/t. P=W/t 2P=1/2W/t This equation is not equal therefore halved is not the correct answer. return to top


















Answer 2
doubled

CORRECT

To find out what happened to the energy if the power doubled you have to use the equation P=W/t.
P=W/t 2P=2W/t -this equation is still equal. Therefore this answer has to be correct. return to top



























Answer 3
quartered

INCORRECT

To find out what happened to the energy if the power doubled you have to use the equation P=W/t. P=W/t 2P=1/4W/t this equation is still not equal, therefore it is not the correct answer. return to top
























Answer 4
quadrupled

INCORRECT

To find out what happened to the energy if the power doubled you have to use the equation P=W/t.

P=W/t
2P=4W/t This equation is not still equal, therefore it can not be the correct answer. return to top





What's this question really asking?
What happens to the energy in an electric circuit if the power is doubled?
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