Electrical Engineering - Energy and Power - Discussion

Discussion :: 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

[A]. 8.57%
[B]. 42.85%
[C]. 4.28%
[D]. 85.7%

Answer: Option D

Explanation:

No answer description available for this question.

Ankita said: (May 4, 2011)  
Efficiency=output/input

=. 6\.7
=. 857

% efficiency =. 857*100
= 85.7%

Vinayak said: (Aug 6, 2011)  
@Ankita Very nice.

Bharat Prajapati said: (Sep 22, 2011)  
Ankita is Right

Sandyachethu said: (Nov 14, 2011)  
Efficiency(n)=output/input
Efficiency(n)=0.6W/0.7W (BOTH "w" CANCEL)
n=0.8571
n%=0.8571x100
n=85.71%

Ovii said: (Nov 19, 2011)  
Adding to sandyachethu: ratio is always without units so thats why both 'w' would cancel eachother.

Elavendhan said: (Jan 3, 2012)  
Efficiency(n) % = (Output Power / Input Power)*100
Efficiency(n) % = (0.6W / 0.7W)*100
Efficiency(n) % = 85.71

Hanumantappa said: (Apr 26, 2012)  
Efficiency =o/p/i/p=0.6*100/0.7=8.71

Ravi Purohit said: (Jun 18, 2012)  
Because efficiency = output / input.

= 0.6 / 0.7 = 0.857 = 0.857*100 % = 85.7 %

Sumathi said: (Jul 13, 2012)  
Efficiency = Output/Input.

=0.6/0.7 = 0.857.

In Percentage, 0.857*100 = 85.7%.

Latjor said: (Jan 1, 2013)  
Efficiency = Output / Input
= 0.6 / 0.7
= 0.857.

Than in percentage efficiency = 0.857 * 100
= 85.7 %.

Sivaprakash said: (Sep 11, 2013)  
Efficiency = output power/ input power = (0.6/0.7)*100 = 85.71%

Bhatruhari Swain said: (Dec 8, 2013)  
Efficiency = output/input.

= .6\.7.
= .857.

% efficiency = .857*100.
= 85.7%.

Ankita said: (Jan 17, 2014)  
E = O/I.
= 0.6/0.7.
= 0.857.

E OF 100 % = 0.857*100.
= 85.7%.

Ramakanth said: (Feb 12, 2014)  
E = output/input =output/output+losses.

So in the question they have to give that losses are neglected.

Then the answer is correct.

Rani said: (Jul 9, 2014)  
Option D was correct because the efficiency will be calculated by using formula (output/input).

So,
0.6/0.7 = 0.857.

Under % = 85.7%

Hemalatha said: (Aug 6, 2014)  
@Hemalatha absolutely right the answer is 85.7%.

Baidya Nath Mohanta said: (Aug 13, 2014)  
Efficiency = OP/IP *100.
= (0.6/0.7)*100.
= 85.7.

Jomel Voltboy said: (Apr 22, 2015)  
E = Output/Input*100.
E = 0.6/0.7*100.
E = 85.7%

Mubiana said: (Sep 27, 2015)  
Efficiency = (output/input)*100.

Efficiency = (0.6/0.7)*100.

= 85.7%.

Alpesh Kachhadiya said: (Apr 21, 2016)  
Efficiency = Output/Input.
So, E =.6/.7*100.
= 85.7%.

Babloo Chandra said: (Jun 1, 2016)  
Efficiency = output/input.

= .6/.7.

= .857.

% = .857 * 100.

= 85.7%.

Kaniksadgir said: (Sep 28, 2016)  
You gave a simple answer.

Thanks @Babloo Chandra.

Satyabrata said: (Mar 30, 2017)  
Efficiency = o.p/i.p * 100.

Gambiza Absalom said: (Jan 9, 2018)  
Efficiency=Otput/Input X 100.
= 85.7%.

Sakthiraja M said: (Dec 12, 2018)  
Normally the efficiency formula is;

Efficiency =outputpower/inputpower * 100.

Dayu said: (Jan 20, 2019)  
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%.

Alibaba said: (Jul 16, 2019)  
Why no one has manually solved this 0.6/0.7 to get 0.857.
06/10 ÷ 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%.

Anomis said: (Sep 8, 2019)  
(0.6÷0.7)*100 = 85.7%.

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