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An electric motor in a crane while lifti...

An electric motor in a crane while lifting a load produces a tension of `4000 N` in the cable attached to the load. If the motor is winding the cable at the rate of `3ms^(-1)`, the power of the motor expressed in kilo watt units must be

A

4

B

3

C

12

D

6

Text Solution

Verified by Experts

The correct Answer is:
`(3)`
`P = FV = 4 xx 10^(3) xx3 = 12 xx 10^(3) W`
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NARAYNA-WORK , ENERGY & POWER -EXERCISE - 1 (C.W)
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  2. A cable pulls a box with force of 5 kN and raises it at the rate of 2 ...

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  3. An electric motor in a crane while lifting a load produces a tension o...

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  4. An electric motor operates with an efficiency of 90%. A pump operated ...

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  5. A machine gun fires 420 bullets per minute. The velocity of each bulle...

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  6. A 1 kg mass at rest is subjected to an acceleration of 5m//s^(2) and t...

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  7. If the power of the motor of a water pump is 3kW, then the volume of w...

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  8. A body of mass m is tied to one end of a string of length l and revolv...

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  9. A mass m is revolving in a vertical circle at the end of a string of l...

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  10. A body of mass m is rotated in a vertical circle of radius R by means ...

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  11. A body of mass m is rotated in a vertical circle with help of light st...

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  12. A vehicle is travelling with uniform speed along a concave road of rad...

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  13. A car is travelling along a flyover bridge which is a part of vertical...

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  14. A very small particle rests on the top of a hemisphere of ra...

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  15. Two steel balls A and B of mass 10 kg and 10 g rolls towards each othe...

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  16. Two identical balls moving in opposite direction with speed 20 m/s and...

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  17. A ball of mass 5 kg moving with speed 8 m/s collides head on with anot...

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  18. A ball is dropped on a horizontal surface from height h. If it rebound...

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  19. A ball of 4 kg mass moving with a speed of 3ms^(-1) has a head on elas...

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  20. A ping-pong ball strikes a wall with a velocity of 10 ms^(-1). If the ...

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