Home
Class 11
PHYSICS
A crane can lift up 10,000 kg of coal in...

A crane can lift up `10,000 kg` of coal in `1` hour form a mine of `180 m` depth. If the efficiency of the crane is `80 %`, its input power must be `(g = 10 ms^(-2))`.

A

5 kW

B

8.3 kW

C

50 kW

D

62.5 kW

Text Solution

Verified by Experts

The correct Answer is:
`(2)`
`eta = P_(out)/P_("in"), where P_(out) = W /t = mgh/t`
Promotional Banner

Topper's Solved these Questions

  • WORK , ENERGY & POWER

    NARAYNA|Exercise EXERCISE -II (C.W)|75 Videos

  • WORK , ENERGY & POWER

    NARAYNA|Exercise EXERCISE -II (H.W)|75 Videos

  • WORK , ENERGY & POWER

    NARAYNA|Exercise EXERCISE - 1 (C.W)|70 Videos

  • WAVES

    NARAYNA|Exercise Exercise-IV|56 Videos

  • WORK POWER AND ENERGY

    NARAYNA|Exercise Level-VI (Integer)|12 Videos

Similar Questions

Explore conceptually related problems

An engine pumps up 100 kg water through a height of 10 m in 5 s . If effcienecy of the engine is 60% . What is the power of the engine? Take g = 10 ms^(2) .

A motor of power 10 kW is used to pump water from a well 20 m deep . Calculate the efficiency of the motor if it pumps 200 kg of water every minute . Take g = 10 m//s^(2)

An engine pumps up 1 quintal of coal from a coal mine 100 m deep in 0.5 seocnd. If its efficienty is 60% then the power of the engine is (take g=10m//s^(2))

A pump can take out 7200 kg of water per hour from a well 100 m. deep. The power of pump, assuming its efficiency as 50% will be

A pump can throw up 10 quntals of coal per hour from a coal mine 120m deep. Calculate the power of the engine in watt assuming that efficiency is 80% .

NARAYNA-WORK , ENERGY & POWER -EXERCISE -1 (H.W)
  1. Two riffles fire the same number of bullets in a givem interval of tim...

    Text Solution

    |

  2. A car weighing 1000 kg is going up an incline with a slope of 2 in 25 ...

    Text Solution

    |

  3. A crane can lift up 10,000 kg of coal in 1 hour form a mine of 180 m d...

    Text Solution

    |

  4. A man carries a load of 50 kg through a height of 40 m in 25 seconds. ...

    Text Solution

    |

  5. An electric motor creates a tension of 4500 newton in a hoisting cable...

    Text Solution

    |

  6. A juggler throws continuously balls at the rate of three in each secon...

    Text Solution

    |

  7. A bucket tied at the end of a 1.6m long string is whirled in a verticl...

    Text Solution

    |

  8. A body of mass 2 kg attached at one end of light string rotated along ...

    Text Solution

    |

  9. A pilot of mass m can bear a maximum apparent weight 7 times of mg. Th...

    Text Solution

    |

  10. The length of ballistic pendulum is 1 m and mass of its block is 0.98 ...

    Text Solution

    |

  11. A simple pendulum is oscillating with an angular amplitude 60^@. If ma...

    Text Solution

    |

  12. A body is moving in a vertical circle such that the velocities of body...

    Text Solution

    |

  13. A ball of mass 0.6 kg attached to a light inextensible string rotates ...

    Text Solution

    |

  14. Two particles of same mass m moving with velocities u(1) and u(2) coll...

    Text Solution

    |

  15. A ball impinges directly on a similar ball at rest. If 1/4 ^(th) of th...

    Text Solution

    |

  16. n bullets per sec each of mass m moving with velocity v strike normall...

    Text Solution

    |

  17. A heavy nucleus at rest breaks into two fragments which fly off with v...

    Text Solution

    |

  18. A 6 kg mass travelling at 2.5 ms^(-1) collides head on with a stationa...

    Text Solution

    |

  19. A body of mass 10 kg moving with a velocity of 5 ms^(-1) hits a body o...

    Text Solution

    |

  20. A block of mass 1 kg moving with a speed of 4 ms^(-1), collides with a...

    Text Solution

    |