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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

4 kW

B

`6.25 kW`

C

50 k

D

`62.5 kW`

Text Solution

Verified by Experts

The correct Answer is:
`(2)`
`P_(@) = (mgh)/t `
`eta = mgh/t/P_("in") Rightarrow P_("in") = (mgh)/(eta t)`
`= 10000 xx10xx180/0.8 xx3600 = 6.25 kW`
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NARAYNA-WORK , ENERGY & POWER -EXERCISE - 1 (C.W)
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  3. A crane can lift up 10,000 kg of coal in 1 hour form a mine of 180 m d...

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  4. A pump is required to lift 600 kg of water per minute from a well 25 m...

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