# Electrical Engineering - Energy and Power - Discussion

Discussion Forum : Energy and Power - General Questions (Q.No. 5)
5.
A power supply produces a 0.6 W output with an input of 0.7 W. Its percentage of efficiency is
8.57%
42.85%
4.28%
85.7%
Explanation:
No answer description is available. Let's discuss.
Discussion:
30 comments Page 1 of 3.

Jeyaprabhu said:   1 year ago
Thanks everyone for explaining the answer.

Ashok Kumar said:   1 year ago
(0.6 Ã· 0.7)*100= 85.7%.
(1)

Anomis said:   5 years ago
(0.6Ã·0.7)*100 = 85.7%.
(2)

AliBaBa said:   5 years ago
Why no one has manually solved this 0.6/0.7 to get 0.857.
06/10 Ã· 07/10.
06/10 * 10/07 cross multiplication will cancel both 10.
06/07 = 0.857,
For efficiency, %age multiply it with 100.
= 85.7%.
(1)

Dayu said:   5 years ago
eff=output power/input power * 100.
So output power is 0.6w and input power is 0.7 watt.
0.6/0.7 * 100 = 85.7%.
(4)

Sakthiraja m said:   5 years ago
Normally the efficiency formula is;

Efficiency =outputpower/inputpower * 100.
(1)

Gambiza Absalom said:   6 years ago
Efficiency=Otput/Input X 100.
= 85.7%.

Satyabrata said:   7 years ago
Efficiency = o.p/i.p * 100.

Thanks @Babloo Chandra.
(1)

Babloo chandra said:   8 years ago
Efficiency = output/input.

= .6/.7.

= .857.

% = .857 * 100.

= 85.7%.