Physics Review Question

Unit: Electricity and magnetism
Year: 1995 Question#: 29
Question: Which unit is equivalent to a watt, the SI unit of power?

(1 ) joule/second
(2) joule/volt
(3 ) joule/ohm
(4 ) joule/coulomb

What is this question really asking?



Explanation by: Dana H

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Answer 1
joule/sec

CORRECT
Correct, The joule per second is eqivalent to a watt, the SI unit of power.
This comes from the definition formula for power is P=W/t where W (work or energy) is measured in joules and t (time) is measured in seconds. return to top























Answer 2
joule/ volt

INCORRECT

Incorrect, a joule/ volt does not equal a watt. Consider the definition formula for Power P=W/t return to top



























Answer 3
joule/ohm

INCORRECT

Incorrect, an ohm is equal to resistance in SI units. Consider the definition formula for Power P=W/t return to top


























Answer 4
joule/coulomb

INCORRECT

Incorrect, a joule/coulomb equals a volt not a watt. Consider the definition formula for Power P=W/t return to top


























What's this question really asking?
What is a watt? return to top

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