Given Inductance L = 2 H Rate of change of current di/dt = 5 A/sec Self induced EMF = − (Rate of change of current × Inductance) = −L(di/dt) = −(5 × 2) = −10V
When variable loss becomes equal to the constant loss, efficiency is maximum. Losses = Pi + Pc Since copper loss is a variable loss therefore Losses = Pi + Pi = 2pi Thus at a maximum efficiency of this transformer total loss = 150 x 2 = 300 W
Penstock Penstock pipe is used to bring water from the dam to the hydraulic turbine. Penstock pipes are made up of steel or reinforced concrete. The turbine is installed at a lower level from the dam. The penstock is provided with a gate valve at the inlet to completely close the water supply. It has a control valve to control the water flow rate into the turbine.
EXAMIANS
