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For the protection of power station buildings against direct strokes the requirements are interception, conduction and dissipation.

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Answer : Surge absorbers are used for protection against low voltage high frequency oscillations

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Description : "Hydro electric power station are not perennial power station". Justify.

Answer : Justification: The water utilized by the hydro power plants comes mostly from storage dams/reservoirs which get filled up during the monsoon rainy season. Such reservoirs are utilized for supplying ... are important. Hence "Hydro electric power stations are not perennial power station" 

Description : State the types of radioactive waste generated in a nuclear power station. Explain the methods employed for their disposal.

Answer : Types of radioactive waste: The waste produced in nuclear power plant is in the form of solid, liquid & gases, 1. Solid Waste Disposal:-  Solid wastes removed from the reactor are very ... are measured. If it is safe then released to atmosphere at high level through large height chimney.

Description : State any four factors governing Selection of site for thermal power station. 

Answer : Following Factors are to be considered:- 1. It should locate near coal mine. 2. Sufficient quantity of water should be available. 3. Sufficient large space should be available. 4. It should be located ... laws of the land and the town planning. 14. The interests of national defense must be served.

Answer : For high value of diversity factor, a power station of given installed capacity will be in a position to supply more number of consumers.

Description : A relay used for protection of motors against overload is :  (A) Impedance relay (B) Electromagnetic attraction type (C) Thermal relay (D) Buchholz's relay

Answer : A relay used for protection of motors against overload is : Thermal relay

Description : For protection of rotating machines against lightning surges _______ is used.  (1) lightning arrester (2) capacitor (3) combination of lightning arrester and capacitor (4) lightning conductor and arrester

Answer : For protection of rotating machines against lightning surges combination of lightning arrester and capacitor is used. 

Description : Reactance relay is normally preferred for protection against

Answer : Reactance relay is normally preferred for protection against earth faults

Description : Compare the Nuclear power station with Hydro power station. 

Answer : SR. No.  Points Nuclear Power plant  Hydro Power station  1 Site/ Location Where there is ample supply of water is available, away from thickly populated areas to avoid radioactive ... Field Application As base load  Used as base load during as well as peak load 

Description : Classify condensers used in thermal power station. Explain each type in brief. 

Answer : Types of condenser: Classification: 1. Jet Condenser (Mixing Type) 2. Surface condenser (non Mixing type)  Explanation:-   1. Jet Condenser (Mixing Type) In Jet condenser the steam ... there in no direct contact between the steam and cooling water. This condensate is reused in boiler. 

Description : Explain the working of Hydro power station with schematic layout. 

Answer : Working of Hydro- Electric Power Plant: Water stored at high level by constructing dam across river. This stored water has potential energy. This stored water is passed to run the water ... energy and Alternator is coupled to water turbine which converts mechanical energy into electrical energy. 

Description : "Efficiency of thermal power station is low". — Justify. 

Answer : Justification: Efficiency of thermal power station is low":- Overall efficiency of T.P.P depends upon efficiency of boiler, turbine and alternator. The heat produced due to combustion of coal ... losses in thermal power plant is 71%, So efficiency of thermal power plant is less about 29% 

Description : Applications of Diesel power station

Answer : Applications of Diesel Power Station:  1. It can be used as a standby (emergency) power plant to maintain continuity of supply. (Incase failure of main supply like hospital, Telephone exchange Radio ... 10. Diesel plants are widely used for generating power ranging from 100 to 5,000 H.P. 

Description : List out main components of Diesel power station. 

Answer : Main components of Diesel power station: 1) Diesel Engine 2) Engine Air intake system 3) Engine Fuel System 4) Engine Exhaust system 5) Engine cooling system 6) Engine Lubricating system 7) Engine Starting system 8) Diesel Engine Generator (Alternator) 

Description : State the function of following components of a nuclear power station: i) Moderator ii) Shielding iii) Control rod iv) Coolant 

Answer : i) Function of Moderator :- Moderator is to moderate or reduce the speed of fast neutron to help the fission process.  ii) Function of sheilding : Shielding is to protect environment, ... from reactor core and transfer it in heat exchanger for producing steam at high pressure and temperature. 

Description : List and state any four limitations of inter connected power station.

Answer : Limitations of inter connected power station:- 1) Initial cost of infrastructure of transmission line increases as length increases. 2) Interconnection required more automation which increases cost on ... capacity. But in absence of surplus power merits of interconnection cannot be obtain.

Description : State the functions of fuel system and exhaust system of a diesel power station.

Answer : Fuel system: It supplies fuel to engine for combustion purpose. It consists of Fuel Pump: - It supplies fuel to engine for combustion purpose. Strainer: - Are provided to remove suspended impurities and ... most of the noise. Chimney:- To exhaust gases in the atmosphere as high as possible. 

Description : State the function of cooling tower and condenser in thermal power station.

Answer : 1. Condenser:   Function of condenser is to convert exhaust steam again into water by reducing its temperature with the help of cold water. Also it reduces back pressure of steam turbine 2 ... tower : The function of cooling tower is to reduce the temperature of water coming from condenser.

Description : State the purpose of surge tank and spill way in hydroelectric power station.

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Description : Write down any two advantages of nuclear power station.

Answer : Advantages of nuclear power station :-  1) Fuel required: Fuel requirment of Nuclear Power Plant is less than Thermal Power Plant. So it reduces transportation cost of fuel and space required for fuel storage ... By use of nuclear fuel.,it saves the other fossile fuels like-coal, gas, oil, etc.

Description : Power station having Load factor = 70%, capacity factor = 50%, used factor = 60%, maximum demand = 20MW then annual energy production is  (1) 122.8 GWh (2) 198.55 GWh (3) 128.2 GWh (4) 188.82 GWh

Answer : Power station having Load factor = 70%, capacity factor = 50%, used factor = 60%, maximum demand = 20MW then annual energy production is 122.8 GWh

Answer : Load factor of a power station is generally less than unity.

Answer : Load factor of a power station is defined as average load/maximum demand.

Answer : A fuse in a motor circuit provides protection against short-circuit and overload.

Answer : A thermal protection switch can protect against overload.

Answer : The single phasing relays are used for the protection of three phase motors.

Answer : The delay fuses are used for the protection of motors.

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Answer : Overfluxing protection is recommended for generator transformer of the power plant.

Answer : Over voltage protection is recommended for hydro-electric generators, steam turbine generators, gas turbine generators.

Description : Blind spot is a point in the zones of protection where

Answer : Blind spot is a point in the zones of protection where No protection is available.

Answer : Protection by fuses is generally not used beyond 100 A .

Description : Primary and Backup Protection

Answer : Primary and Backup Protection  B,D,G,I are the primary protection. A,C,H,J are the backup protection. About 90% of faults are clear by Primary Protection. So ... ordinated backup (primary is at various station  and backup is at control room with computer)

Answer : A direct online starter is used for starting motors up to 5 H.P.

Description : Explain in detail over-voltage protection.

Answer : Over-voltage protection: Over-voltage protection to the thyristor is provided using: i) R-C Snubber circuit ii) Non-linear resistor Thyrector A) Snubber Circuit: It is basically a ... returns to its high resistance state. Thyrector is normally placed across the supply terminals.

Description : Differentiate between direct and indirect extrusion. Discuss their relative merits and demerits. 

Answer : Direct extrusion Indirect extrusion Simple, but the material must slide along the chamber wall. In this case, material does not move but die moves. High friction forces must ... be used for extruding long extrudes. Support of the ram becomes a problem as work length increases.

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Answer : Instructions ii) and iv) are direct addressing as 80H and 45H are direct addresses

Description : Direct Extrusion process

Answer : Direct Extrusion process Direct extrusion process is shown in fig. The raw material used is a billet. It consists of a press operated ram and a cylinder or container into which the heated ... for extruding long extrudes. 2) Support of the ram becomes a problem as work length increases.

Description : Direct Current (DC) Next Topic : Alternating current (AC)

Answer : Direct Current (DC) is the unidirectional electric current. Uni meaning is one. And the flow of charge in same direction. We know that conventional current flow from positive terminal of battery to ... The magnitude of DC may constant or vary but direction do not change with respect to time.

Description : advantages and disadvantages of direct coupled amplifier over RC coupled amplifier. 

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