MCQs on Power Systems

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01․ Which of following power plants normally operage at high speeds
Hydro electric.
Diesel engine.
Petrol engine.

In thermal power plant, the steam turbine is operated as high speed as high speed abot of 1500 to 3000 rpm.

02․ Ships are usually supplied power by
Hydraulic turbine.
Steam accumulator.
Diesel engine.
None of above.

Ship are usually supplied power by diesel engine because - (i) A diesel power engine can be started and stopped quickly as when required. (ii) Diesel engine does not require a large amount of cooling. (ii) Diesel engine maintain their efficiency even ar fraction load

03․ The power station that does not requier any moving part is
Solar power generation.
Thermonic convertor.
Wind power generation.
Tidal power generation.

In thermonic converter, heat energy transforms directly into electrical energy by utilizing thermonic emission. In a thermonic converter two electrodes are plased in a container containing an ionised gas or cesium vapour to reduce space change. The cathode is heated by concetrating the rays on it. On heating of cathode the electrons are emitted from it and travel to anode . The cathode and anode are connected externally through the load circuit. The electrons return back to cathode through the ecternal circuit and the current flows through the external circuit. The heat energy is coverted directly into electriacl energy with out any rotating part.

04․ Which of the following will take least time in starting from cold condition to full load operation
Gas turbine plant.
Nuclear power plant.
Hydro electric power plant.
Thermal power plant.

The hydro electric power plant will take least time of about 5-10 minutes in starting from cold conditions to full load operation. Hence this plants used to supply the peak load of the system.

05․ Which power plant cannot have single unit of 100 MW capacity
Diesel engine plant.
Steam power plant.
Hydro electric power plant.
Nuclear power plant.

Disel power plant cannot have single unit of 100 MW capacity because of escalating fuel cost, high maintenance and lubrication cost, limited useful supplying overloads.

06․ The generating station suitable to operate as peak load plant is
Nuclear power station.
Pumped storage.
Power station.
Thermal power station.

In pumped storage plant, the plant pumps back all or a portion of its water supply during low load period. The usual construction is a tail water pond and a head water pond connected through a penstock. The generating pumping plant is at lower end. The plant utilizes some of the surplus energy generated by the base load plant to pump the water from the tail water pond into the head water pnod during off peak hours. During peak load period this water pond through the water turbine of this plant to the tail water pond.

07․ The essential requirement(s) for power plants to be operated as peak load plants are
Low capital cost.
Capability of quick starts.
Quick response to load variation.
All of the above.

The power plant to be employed as peak load power plants should have the capability of quick start, synehronistion and taking up of system load, quick response to load variations and low cost.