Work, Energy and Power-Power (KVPY Stream-SA (Class 11) Physics): Questions 1 - 5 of 7

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Question number: 1

» Work, Energy and Power » Power

Appeared in Year: 2011

MCQ▾

Question

A 750 W motor drivers a pump which lifts 300 liters of water per minute to a height of 6 meters. The efficiency of the motor is nearly (take acceleration due to gravity to be 10 m/s 2)

Choices

Choice (4) Response
a.

30%

b.

20%

c.

50%

d.

40%

Question number: 2

» Work, Energy and Power » Power

MCQ▾

Question

A 250 W motor drivers a pump which lifts 90 liters of water per minute to a height of 4 meters. The efficiency of the motor is nearly (take acceleration due to gravity to be 10 m/s2)

Choices

Choice (4) Response
a.

28 %

b.

26 %

c.

24 %

d.

22 %

Question number: 3

» Work, Energy and Power » Power

MCQ▾

Question

A boy of weight 50 kg climbs up a staircase carrying 15 kg load on his head. The staircase has 35 steps and each step has a height of 15 cm. If he takes 20 seconds to climb, calculate the power developed by him. (g = 9.8 ms-2)

Choices

Choice (4) Response
a.

167.21

b.

323.3

c.

527.5

d.

95.32

Question number: 4

» Work, Energy and Power » Power

MCQ▾

Question

A person X of mass 81 kg walks up a stair case in 27 sec. Another person Y of mass 63 Kg walks up the same staircase in 7 sec. The ratio of the power generated by X to that by Y is,

Choices

Choice (4) Response
a.

19

b.

13

c.

3

d.

23

Question number: 5

» Work, Energy and Power » Power

MCQ▾

Question

A person P of mass 72 kg walks up a stair case in 36 sec. Another person Q of mass 54 Kg walks up the same staircase in 6 sec. The ratio of the power generated by P to that by Q is,

Choices

Choice (4) Response
a.

2

b.

16

c.

14

d.

29

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