Greetings physics gurus(adsbygoogle = window.adsbygoogle || []).push({});

Im getting bogged down on conversion of the VA to A

1. The problem statement, all variables and given/known data

A small transformer used to power a laptop computer has the following characteristics printed on it:

• input AC 220 V, 50 Hz, 15 VA.

• output DC 5.0 V, 1.0 A.

Is this transformer efficient? Support your answer with calculations. Determine value for efficiency

2. Relevant equations

Efficiency = energy output/energy input x 100%

3. The attempt at a solution

Im not sure if the Hz impact on the solution - but Im getting a very low efficiency. 33%

Just need a little guidence to get me going with this question.

Cheers P

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# Homework Help: Transformer efficiency conversion

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