3A ELECTRICAL PRACTICE
TEST STUDY GUIDE
COMPLETE
Question 1: What is the primary purpose of a megohmmeter?
Choices:
1) Measure insulation resistance 2) Measure phase rotation 3) Measure light level 4) Measure conductor length
Correct Answer: Measure insulation resistance
Explanation: A megohmmeter applies a DC test voltage and measures very high resistance to evaluate insulation condition.Page 1
Question 2: How should a voltmeter be connected to measure voltage across a
load?
Choices:
1) In series 2) In parallel 3) Only to ground 4) Across the breaker handle
Correct Answer: In parallel
Explanation: Voltage is potential di�erence between two points, so the meter is connected in parallel across those points.
Question 3: How should a clamp ammeter normally be placed to measure load
current?
Choices:
1) Around one current-carrying conductor 2) Around all circuit conductors together 3) Around the grounding electrode only 4) Across two phase terminals
Correct Answer: Around one current-carrying conductor
Explanation: A clamp meter senses the magnetic �eld around current. Clamping one current- carrying conductor prevents �eld cancellation.Page 2
Question 4: What does a live-dead-live test verify?
Choices:
1) The breaker frame size 2) The tester works before and after verifying absence of voltage 3) The conductor insulation color 4) The motor direction
Correct Answer: The tester works before and after verifying absence of voltage
Explanation: Live-dead-live con�rms the tester operates on a known source before and after the de-energized-circuit check.Question 5: A 120 V source is applied to a 24 ohm resistor. What current �ows?
Choices:
1) 2 A
2) 5 A
3) 12 A
4) 24 A
Correct Answer: 5 A
Explanation: Ohm law gives I = V/R = = 5 A.
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