TS ECET EEE 2020-6

1. corona loss increases with

A. Increase in supply frequency and conductor size
B. Increases in supply frequency and decrease in conductor size
C. Decrease in supply frequency and conductor size
D. Decrease in supply frequency but increase in conductor size

Answer : B. Increases in supply frequency and decrease in conductor size
Explanation:-

2. When an alternating current flows through a conductor

A. Entire current passes through the core of the conductor
B. Portion of conductor near the surface carries more current in comparision to the core
C. Current remains uniformly distributed over the whole cross-section of the conductor
D. Portion of conductor near the surface carries less current in comparision to the core

Answer : B. Portion of conductor near the surface carries more current in comparision to the core
Explanation:-

3. In a string of suspension insulators, which of the following statement is correct

A. The disc nearest to the conductor has maximum voltage across it
B. The disc nearest to the cross arm has maximum voltage across it
C. The middle disc of the insulator has maximum voltage across it
D. The voltage is distributed equally in the insulator

Answer : A. The disc nearest to the conductor has maximum voltage across it
Explanation:-

4. The sag of the conductor of a transmission line is 2.5m when the span is 250m. Now if the height of supporting tower is increased by 25%, the sag will

A. Reduce by 25%
B. Increase by 25%
C. Reduce by 12.5%
D. Remain unchanged

Answer : D. Remain unchanged
Explanation:-

5. The most commonly used material for insulator of overhead line is

A. porcelain
B. glass
C. mica
D. PVC

Answer : A. porcelain
Explanation:-

6. High voltage DC transmission is mainly used for

A. Bulk power transmission over long distances
B. Interconnecting two systems with the same nominal frequency
C. Eliminating reactive power requirement in the operation
D. Minimising harmonics at the converter stations

Answer : A. Bulk power transmission over long distances
Explanation:-

7. The sequence of operation of isolator, circuit breaker (C.B) and earth switch while opening a circuit

A. Earth switch opens, isolator opens, CB opens
B. C.B opens, isolator opens, Earth switch closes
C. Earth switch closes, isolator opens, C.B opens
D. Isolator opens, Earth switch closes, C.B opens

Answer : B. C.B opens, isolator opens, Earth switch closes
Explanation:-

8. Pole mounted substations are normally recommended for transformers upto a maximum capacity of

A. 25 KVA
B. 250 KVA
C. 1 MVA
D. 100 MVA

Answer : B. 250 KVA
Explanation:-

9. The insulating materials with same maximum working stress and permitivities 2.5,3.0,4.0 are used in a asingle core cable. The loaction of the material with respect to the core of the cable will be

A. 2.5,3.0,4.0
B. 3.0,2.5,4.0
C. 4.0,3.0,2.5
D. 4.0,2.5,3.0

Answer : C. 4.0,3.0,2.5
Explanation:-

10. Ring main distribution is preferred to a radial system because

A. Voltage drop in the feeder is less and supply is more reliable
B. Voltage drop in the feeder is less and power factor is high
C. Power factor is high and supply is more reliable
D. Power factor is high and system is less expensive

Answer : A. Voltage drop in the feeder is less and supply is more reliable
Explanation:-