water falls from a height of 60m at the rate of 15kgs to

Water falls from a height of $$60\,m$$ at the rate of $$15\,kg/s$$ to operate a turbine. The losses due to frictional forces are $$10\% $$ of energy. How much power is generated by the turbine ? (Take $$g = 10\,m/{s^2}$$ )

A. $$8.1\,kW$$

B. $$10.2\,kW$$

C. $$12.3\,kW$$

D. $$7.0\,kW$$

Answer : $$8.1\,kW$$

Solution :
$$\eqalign{ & {P_{{\text{generated}}}} = {P_{{\text{input}}}} \times \frac{{90}}{{100}} \cr & = \frac{{mgh}}{t} \times \frac{{90}}{{100}} = \frac{{15 \times 10 \times 60}}{1} \times \frac{{90}}{{100}} \cr & = 8.1\,kW \cr} $$

Releted MCQ Question on
Basic Physics >> Work Energy and Power

Releted Question 1

If a machine is lubricated with oil-

A. the mechanical advantage of the machine increases.

B. the mechanical efficiency of the machine increases.

C. both its mechanical advantage and efficiency increase.

D. its efficiency increases, but its mechanical advantage decreases.

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Releted Question 2

Two masses of $$1 \,gm$$ and $$4 \,gm$$ are moving with equal kinetic energies. The ratio of the magnitudes of their linear momenta is-

A. $$4:1$$

B. $$\sqrt 2 :1$$

C. $$1:2$$

D. $$1:16$$

View Answer

Releted Question 3

A particle of mass $$m$$ is moving in a circular path of constant radius $$r$$ such that its centripetal acceleration $${a_c}$$ is varying with time $$t$$ as $${a_c} = {k^2}r{t^2}$$ where $$k$$ is a constant. The power delivered to the particles by the force acting on it is:

A. $$2\pi m{k^2}{r^2}t$$

B. $$m{k^2}{r^2}t$$

C. $$\frac{{\left( {m{k^4}{r^2}{t^5}} \right)}}{3}$$

D. Zero

View Answer

Releted Question 4

A spring of force-constant $$k$$ is cut into two pieces such that one piece is double the length of the other. Then the long piece will have a force-constant of-

A. $$\left( {\frac{2}{3}} \right)k$$

B. $$\left( {\frac{3}{2}} \right)k$$

C. $$3k$$

D. $$6k$$

View Answer

Water falls from a height of $$60\,m$$ at the rate of $$15\,kg/s$$ to operate a turbine. The losses due to frictional forces are $$10\% $$ of energy. How much power is generated by the turbine ? (Take $$g = 10\,m/{s^2}$$ )

Releted MCQ Question on
Basic Physics >> Work Energy and Power

If a machine is lubricated with oil-

Two masses of $$1 \,gm$$ and $$4 \,gm$$ are moving with equal kinetic energies. The ratio of the magnitudes of their linear momenta is-

A particle of mass $$m$$ is moving in a circular path of constant radius $$r$$ such that its centripetal acceleration $${a_c}$$ is varying with time $$t$$ as $${a_c} = {k^2}r{t^2}$$ where $$k$$ is a constant. The power delivered to the particles by the force acting on it is:

A spring of force-constant $$k$$ is cut into two pieces such that one piece is double the length of the other. Then the long piece will have a force-constant of-

Practice More Releted MCQ Question on
Work Energy and Power

Practice More MCQ Question on Physics Section

Water falls from a height of $$60\,m$$ at the rate of $$15\,kg/s$$ to operate a turbine. The losses due to frictional forces are $$10\% $$ of energy. How much power is generated by the turbine ? (Take $$g = 10\,m/{s^2}$$ )

Releted MCQ Question on Basic Physics >> Work Energy and Power

If a machine is lubricated with oil-

Two masses of $$1 \,gm$$ and $$4 \,gm$$ are moving with equal kinetic energies. The ratio of the magnitudes of their linear momenta is-

A particle of mass $$m$$ is moving in a circular path of constant radius $$r$$ such that its centripetal acceleration $${a_c}$$ is varying with time $$t$$ as $${a_c} = {k^2}r{t^2}$$ where $$k$$ is a constant. The power delivered to the particles by the force acting on it is:

A spring of force-constant $$k$$ is cut into two pieces such that one piece is double the length of the other. Then the long piece will have a force-constant of-

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Practice More MCQ Question on Physics Section

Releted MCQ Question on
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Work Energy and Power