Video 3.3

In the video, the speaker mentioned which factor first affects the value of the fault current ? 

• A. Default position of relay

• B. Environmental conditions

• C. Temperature conditions

•  D. Lightning current

2. Suppose, the value set on the Relay is 100 amps, in which of the following cases will the relay send a signal to the breaker?

• A. The current flowing through the relay is 70 ampes

• B. The current flowing through the relay is 80 ampes

• C. The current flowing through the relay is 90 ampes

• D. The current flowing through the relay is 100 ampes

3.When will the overcurrent relay operate ?

• A. Protection current is greater than set value

• B. Protection current is less than set value

• C. Electricity system is working normally

• D. Protection current equal to set value

4. How does an overcurrent relay react across a protected element?

• A. Current

• B. Voltage

• C. Resistance

• D. Capacitance

5.Which of the factors affecting the short circuit current will increase the fault current smaller?

• A. Voltage

• B. Impedance

• C. Frequency

• D. Capacity

6. When an error occurs at the front end of the transmission line, which will cause the circuit to lose impedance, how will the current flow in the circuit?

• A. Very big

• B. No influence

• C. Very small

• D. = 0

7. How many factors affect the fault current?

• A. 1

• B. 2

• C. 3

• D. 4

8. Why is the high impedance relay so hard to detect?

• A. Because this fault current is close to the rated current of circuit

• B. Because this fault current is far from the rated current of the circuit

• C. Because this error line does not change

• D. Because this line error is very large

9. What is the power of a power source measured in?

• A. The impedance of the power source

• B.  Relays

• C. Ammeter

• D. Resistance meter

10. How is the power source when the impedance of the power source is lower?

• A. Lower

• B. Higher

• C. No change

• D. There is no such thing as true