AP ECET EEE 2020-7

1. Metallic sheath in cables is used to protect the cable from

A. Metallic corrosion
B. corrosion
C. Mechanical injuries
D. chemicals

Answer : D. chemicals
Explanation:-

2. Ring system is preferred over radial system because

A. less cost
B. Reliable and less voltage drop
C. voltage can be reduced
D. poor voltage regulation

Answer : B. Reliable and less voltage drop
Explanation:-

3. Which of the following is not tru regarding HVDC

A. There is no distance limit for HVDC under ground line
B. HVDC Link can be operate between two AC Systems whose frequencies are equal
C. Corona loss is much more in HVDC transmission
D. The power transmission of bipolar line is same as that of single circuit ac line

Answer : C. Corona loss is much more in HVDC transmission
Explanation:-

4. Suburban railways use

A. 600 - 750V DC
B. 3000 V DC
C. 3.3KV 3-phase AC
D. 1100V 1-phase AC

Answer : A. 600 - 750V DC
Explanation:-

5. Quadrilateral speed time curve pertains to which of the following service?

A. Main line service
B. Suburban service only
C. Urban service only
D. urban and suburban service

Answer : D. urban and suburban service
Explanation:-

6. The free running speed of a train does not depend on the

A. Running time
B. Duration of stops
C. Acceleration
D. Distance between stops

Answer : B. Duration of stops
Explanation:-

7. The specific energy consumption for suburban services is usually

A. 18 - 25 watt hours per tonne km
B. 125 - 150 watt hours per tonne km
C. 50 - 75 watt hours per tonne km
D. 155 - 200 watt hours per tonne km

Answer : C. 50 - 75 watt hours per tonne km
Explanation:-

8. Which of the following happens in Kando system?

A. 1-phase AC is converted into 3-phase AC
B. 1-phase AC is converted into DC
C. 3-phase AC is converted into DC
D. 3-phase AC is converted into 1-phase AC

Answer : A. 1-phase AC is converted into 3-phase AC
Explanation:-

9. Longer coasting period for atrain results in _________

A. Higher schedule speed
B. Higher retardation
C. Higher Acceleration
D. Lower specific energy consumption

Answer : D. Lower specific energy consumption
Explanation:-

10. The fraction at the track is proportional to

A. 1/speed
B. speed^2
C. speed
D. 1/(speed)^2

Answer : C. speed
Explanation:-