Journeyman Electrician Questions and Answers:
This set of Questions will be useful for Journeyman and Master Electricians exam.
When more voltage than one cell produces is required. How cells are connected?
Answer: Cells are connected in Series to get more voltage
Explain the meaning of the Ampere-Hour?
Answer: At full charge of the battery it is capable of delivering X number of amperes for Y number of hours. For example it a battery is rated for 100amperes hour, it has the capability of delivering 10 amperes for 10 hours or 2 amperes for 50 hours or 100 amperes for 1 hour.
If a DC motor is disconnecting rapidly from the line, what must be provided?
Answer: When DC motor is disconnecting rapidly then it should be short circuited directly or through resistance, so that collapsing magnetic field does not induce any high voltage
Can a Single Phase motor be run on two or three phase line?
Answer: Yes i can be run. It should be connected to only two phase wires
What are the major losses in the transformers?
Answer: Major losses in the transformer are I2R (copper loss), eddy current loss and hysteresis loss
How power factor is measured or determined?
Answer: Power factor can be measured by using voltmeter, ammeter and watt meter or by using power factor meter
Can green color wire be used for electrical circuits and wiring purpose?
Answer: No green color is meant for grounding only and should not be used for electrical circuits
What is meant by motor-circuit switch?
Answer: A switch which is rated in horse power, capable of interrupting the maximum operating overload current of motor having same horse power rating as switch at the rated voltage
What is demand factor?
Answer: Demand factor is the ratio between the maximum demand on the system or part of the system and the total connected load on the same system or part of the system
What is the overall efficiency of the 5 hp motor that draws 20 amperes at 240 volts?
Answer:
Input = 240X20 = 4800 watts
Output= 5X746 = 3730 watts
Efficiency= (Output / Input) = 3730/4800 =0.777 = 77.7%
tags: Electrician exam preparation, Journeyman Electrician Exam preparation
