Work, Energy and PowerPower (KVPY StreamSA (Class 11) Physics): Questions 1  5 of 8
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Question number: 1
» Work, Energy and Power » Power
Appeared in Year: 2011
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
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/s^{2})
Choices
Choice (4)  Response  

a.  28 % 

b.  26 % 

c.  24 % 

d.  22 % 

Question number: 3
» Work, Energy and Power » Power
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
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. 


b. 


c. 


d. 


Question number: 5
» Work, Energy and Power » Power
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. 


c. 


d. 

