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1. Types of fault current include overloads, short circuits, ground faults, and ________.

asymmetric faults

transient faults

arc faults

symmetrical faults

Question 1 of 15

2. Where are overcurrent protective devices normally installed in a branch circuit?

At the circuit load

At circuit devices only

Where the conductors receive their supply

At the supply transformer only

Question 2 of 15

3. The branch circuit conductor and overcurrent protective device must be sized for the actual noncontinuous load plus what percentage of the continuous load?

150%

110%

115%

125%

Question 3 of 15

4. Which type of fuse should be used to prevent nuisance tripping from temporary motor overloads and surge currents?

Dual-element, time-delay fuse

Nontime-delay fuse

GE-base single-element fuse

Edison-base plug fuse

Question 4 of 15

5. If a continuous load on a branch circuit is measured at 40A, the overcurrent protection should be sized at ________.

50A

40A

30A

20A

Question 5 of 15

6. Which of the following is within the basic scope of Underwriters Laboratories?

Safety

Functional performance of fuses

Proper selection of fuses

Reliability of fuses

Question 6 of 15

7. Overcurrent protection is covered in ________.

NEC Article 334

NEC Article 200

NEC Article 314

NEC Article 240

Question 7 of 15

8. When selecting ampere ratings of fuses and circuit breakers, the most important consideration is the ________.

conductor insulation

ambient temperature

size and type of load

type of conductor

Question 8 of 15

9. Circuit breakers are classified by ________.

color coding

the smallest ampere rating of its range

the largest ampere rating of its range

manufacturer

Question 9 of 15

10. Which of the following is commonly referred to as motor branch circuit protection?

Overcurrent protection

Component protection

Short circuit protection

Overvoltage protection

Question 10 of 15

11. What is the maximum number of circuit breakers or sets of fuses that may be used as the service disconnecting means in a main service panel without a main switch?

Question 11 of 15

12. Which of the following is true of the voltage rating of a fuse?

It depends upon its capability to close a circuit under an overcurrent condition.

It can be higher than the circuit voltage but never lower.

It is always the same as the circuit voltage.

It can be lower than the circuit voltage but never higher.

Question 12 of 15

13. Which of the following are designed to withstand numerous trip and reset cycles without replacement and can be thermal, magnetic, or solid-state?

Current-limiting devices

Overload relays

Fast-acting fuses

Semiconductor fuses

Question 13 of 15

14. UL Class R fuses have a short circuit interrupting rating of up to ________.

50,000A

125,000A

200,000A

75,000A

Question 14 of 15

15. If a 120V feeder for nonmotor loads feeds a continuous load rated at 20A and a noncontinuous load at 30A, what size overcurrent protective device should be selected?

70A

80A

45A

60A

Question 15 of 15

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