Water flows through a tunnel from the reservior of a dam towards the turbine installed in its power plant . The power plant is situated h metre below the reservoir . If the ratio of the cross sectional areas of the tunnel at the resercoir and power station end is `eta ` , find the speed of the water entering into the turbine .

Options

A. `etasqrt((2gh)/(eta^2+1))`
B. `sqrt((2gh)/(eta^2-1))`
C. `etasqrt((2gh)/(eta^2-1))
D. `etasqrt((eta^2-1)/(2gh))`