A hydro electric power station takes its water from a lake whose water level is 50m above the turbine. Assuming an overall efficiency of 40%, calculate the mass of water which must flow through the turbine each second to produce power output of 1MW.

Home » A hydro electric power station takes its water from a lake whose water level is 50m above the turbine. Assuming an overall efficiency of 40%, calculate the mass of water which must flow through the turbine each second to produce power output of 1MW.

Class 10 | ICSE | Physics | Selina | Work Energy

A hydro electric power station takes its water from a lake whose water level is 50m above the turbine. Assuming an overall efficiency of 40%, calculate the mass of water which must flow through the turbine each second to produce power output of 1MW.

(g=10 m s^-2).

Solutions:

According to the question,

We know that the expression of Potential energy is mgh

Efficiency is 40%

Useful work done is equal to 40% of potential energy

= 40 / 100 (mgh) = 0.4 (m × 10 × 50)

= 200 m

Power is nothing but work done per second, so –

1MW = 200 × mass of water flowing per second

1 × 10⁶W = 200 × mass of water flowing per second

mass of water flowing per second

= (1 × 10⁶) / 200 = 5000 kg

i

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