8 Energy – forces doing work

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Question 97

H

A motor produces a useful power of 240 W. Its efficiency increases from 0.60 to 0.80, with no change in useful power. What is the percentage decrease in its input power?

[1]

$25%25\%$

$50%50\%$

$20%20\%$

$33%33\%$

8 Energy – forces doing work

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Question 97

H

A motor produces a useful power of 240 W. Its efficiency increases from 0.60 to 0.80, with no change in useful power. What is the percentage decrease in its input power?

[1]

$25%25\%$

$50%50\%$

$20%20\%$

$33%33\%$

8 Energy – forces doing work

Question 97

Markscheme

8 Energy – forces doing work

Question 97

Markscheme

8 Energy – forces doing work

Question 97

8 Energy – forces doing work Questions

8 Energy – forces doing work

Question 97

8 Energy – forces doing work Questions