Transmission And Distribution Of Electrical Energy Set 3
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This set of Transmission and Distribution of Electrical Energy Multiple Choice Questions & Answers (MCQs) focuses on Transmission And Distribution Of Electrical Energy Set 3
Q1 | For an overhead line, the surge impedance is taken as
- 20-30 ohms
- 70—80 ohms
- 100—200 ohms
- 500—1000 ohms
Q2 | The presence of ozone due to corona is harmful because it
- reduces power factor
- corrodes the material
- gives odour
- tr
Q3 | A feeder, in a transmission system, feeds power to
- distributors
- generating stations
- service mains
- all of the above
Q4 | The power transmitted will be maximum when
- corona losses are minimum
- reactance is high
- sending end voltage is more
- receiving end voltage is more
Q5 | A 3-phase 4 wire system is commonly used on
- primary transmission
- secondary transmission
- primary distribution
- secondary distribution
Q6 | Which of the following materials is used for overhead transmission lines ?
- Steel cored aluminium
- Galvanised steel
- Cadmium copper
- Any of the above
Q7 | Which of the following is not a constituent for making porcelain insulators?
- Quartz
- Kaolin
- Felspar
- Silica
Q8 | There is a greater possibility of occurence of corona during
- dry weather
- winter
- summer heat
- humid weather
Q9 | Which of the following relays is used on long transmission lines ?
- Impedance relay
- Mho’s relay
- Reactance relay
- None of the above
Q10 | The steel used in steel cored conductors is usually
- alloy steel
- stainless steel
- mild steel
- high speed steel
Q11 | Which of the following distribution systems is more reliable ?
- Radial system
- Tree system
- Ring main system
- All are equally reliable
Q12 | Which of the following characteristics should the line supports for transmission lines possess ?
- Low cost
- High mechanical strength
- Longer life
- All of the above
Q13 | Transmission voltage of ll kV is normally used for distances upto
- 20—25 km
- 40—50 km
- 60—70 km
- 80—100 km
Q14 | Which of the following regulations is considered best?
- 50%
- 20%
- 10%
- 2%
Q15 | Skin effect is proportional to
- (conductor diameter)
- (conductor diameter)
- (conductor diameter)
- (conductor diameter)
Q16 | A conductor, due to sag between two supports, takes the form of
- semi-circle
- triangle
- ellipse
- catenary
Q17 | In AC.S.R. conductors, the insulation between aluminium and steel conductors is
- insulin
- bitumen
- varnish
- no insulation is required
Q18 | Which of the following bus-bar schemes has the lowest cost ?
- Ring bus-bar scheme
- Single bus-bar scheme
- Breaker and a half scheme
- Main and tr
Q19 | Owing to skin effect
- current flows through the half cross-section of the conductor
- portion of the conductor near the surface carries more current and core of the conductor carries less current
- portion of the conductor near the surface carries less current and core of the conductor carries more cur¬rent
- any of the above
Q20 | By which of the following methods string efficiency can be improved ?
- Using a guard ring
- Grading the insulator
- Using long cross arm
- Any of the above
Q21 | In aluminium conductors, steel core is provided to
- compensate for skin effect
- neutralise proximity effect
- reduce line inductance
- increase the tensile strength
Q22 | By which of the following a bus-bar is rated ?
- Current only
- Current and voltage
- Current, voltage and frequency
- Current, voltage, frequency and short time current
Q23 | A circuit is disconnected by isolators when
- line is energized
- there is no current in the line
- line is on full load
- circuit breaker is not open
Q24 | For which of the following equipment current rating is not necessary ?
- Circuit breakers
- Isolators
- Load break switch
- Circuit breakers and load break switches
Q25 | In a substation the following equipment is not installed
- exciters
- series capacitors
- shunt reactors
- voltatre tr