AP ECET EEE 2020-6

1. For protection of parallel feeders fed at one end, the relays required are

A. directional relays at both ends
B. non-directional relays at both ends
C. non-directional relay at source end and directional relay at load end
D. Directional relay at source end and non-directional relay at load end

Answer : C. non-directional relay at source end and directional relay at load end
Explanation:-

2. The transient voltage that appears across the contacts at the instant of arc excitation is called

A. supply voltage
B. peak voltage
C. recovery voltage
D. re-striking voltage

Answer : D. re-striking voltage
Explanation:-

3. In a lightning arrestor ______ impedance path exists between the line and ground ______

A. Infinite,always
B. low, before the over voltage
C. High, before the over voltage
D. low, at the instant of over voltage

Answer : D. low, at the instant of over voltage
Explanation:-

4. If the spacing between the conductors of a line is increased, the inductance ______ and the capacitance _____

A. Increases,decreases
B. Increses,increases
C. decreases, decreases
D. decreases, increases

Answer : A. Increases,decreases
Explanation:-

5. Under no load condition, the current in a transmission line is due to

A. Corona effect
B. Inductance of the line
C. Capacitance of the line
D. back-flow from the earth

Answer : C. Capacitance of the line
Explanation:-

6. Corona loss increases with _____

A. Increases in conductor size and decreases in supply frequency
B. decreases in conductor size and increase in supply frequency
C. Increase in both conductor size and supply frequency
D. Decrease in both conductor size and supply frequency

Answer : B. decreases in conductor size and increase in supply frequency
Explanation:-

7. Skin effect proportional to

A. (Conductor Diameter)^3
B. (Conductor Diameter)^1/2
C. (Conductor Diameter)^4
D. (Conductor Diameter)^2

Answer : D. (Conductor Diameter)^2
Explanation:-

8. In the sag in an over head line decreases, tension in the line

A. decreases
B. remains the same
C. increases
D. will become zero

Answer : C. increases
Explanation:-

9. Transmission line insulators are made of _______

A. glass
B. iron
C. PVC
D. Porcelain

Answer : D. Porcelain
Explanation:-

10. Which is the first equipment seen in the substation while coming from transmission system?

A. Lightning arrestor
B. Circuit breaker
C. Current transformer
D. Potential transformer

Answer : A. Lightning arrestor
Explanation:-