Journeyman Electrician Practice Test 14

Question 1: One pole circuit breaker protects one 120 volt branch circuit.

• True
• False

Question 2: For a small form building consisting of 2 wire branch circuits, What is the minimum ampacity capacity of service equipment is required?

• A 30-amp Service Equipment supplied by two No.8 Copper wires
• A 30-amp Service Equipment supplied by two No.8 aluminum wires
• A 15-amp Service Equipment supplied by two No.8 Copper wires
• A 15-amp Service Equipment supplied by two No.8 aluminum wires

Question 3: If the motor overload is increased to much, the motor will ....................

• stall and burnout
• draw more current
• be reduced to half the speed

Question 4: Proximity effect is due to the current flowing in the ..............

• earth
• sheath
• neighboring conductor

Question 5: In a Transmission system the reactive power can be injected by using ..........................

• shunt capacitors and reactors
• synchronous capacitors
• series capacitors

Question 6: Regulating transformers are used in power system to control:

• power factor
• load flow
• voltage

Question 7: The speed of the ordinary AC Motor can be controlled by rheostats.

• True
• False

Question 8: A 3 HP motor operating at 104 F has a service factor of 1.2. What is the maximum power that it can continuously without any damage?

• 3.6 HP
• 3.2 HP
• 2.4 HP
• 3 HP

Question 9: Which of the following motors has lowest starting current?

• split phase motors
• RI Motors
• Capacitor Motors

Question 10: Repulsion-Start Induction Run Motors can run on only single phase alternating current.

• True
• False

Question 11: Which of the following is the equation used to calculate the voltage drop in a resistor according to Kirchhoff’s voltage law?

• IR
• I/R
• R/I
• I²R

Question 12: How many number of entrances should be provided to give access from working space about electrical equipment?

• 1
• 2
• 3
• 4

NEC Reference: NEC 110.26

Question 13: The minimum size copper equipment grounding conductor for a 100 amperes circuit is …………….

• 8 AWG
• 10 AWG
• 6 AWG
• 12 AWG

NEC Reference: NEC 250.122

Question 14: The overhead conductors between last pole of power company and building structure used for electrical service are termed as …………..

• Service entrance
• Service drop
• Service head
• Service entrance conductors

Question 15: The pendant conductors longer than ……….. in length to be twisted together.

• 4 feet
• 3 feet
• 5 feet
• 2 feet

NEC Reference: NEC 410.54(C)

Question 16: In a transformer, which winding is connected to the power supply?

• The secondary winding
• The primary winding
• Both primary and secondary are connected to the supply
• Neither winding — only the core connects to the supply

Question 17: In a purely inductive AC circuit, how does voltage relate to current in time?

• Voltage lags current by 90 degrees
• Voltage leads current by 90 degrees
• Voltage and current are in phase
• Voltage and current are 180 degrees apart

Question 18: In a purely capacitive AC circuit, how does current relate to voltage in time?

• Current lags voltage by 90 degrees
• Current and voltage are always in phase
• Current leads voltage by 90 degrees
• Current and voltage are 180 degrees apart

Question 19: In a series RL circuit with resistance R and inductive reactance XL, what is the total impedance Z?

• Z = R + XL
• Z = R × XL
• Z = √(R² + XL²)
• Z = R - XL

Question 20: When conductors pass through a hole in a wood stud less than 1.25 inches from the edge, what protection is required?

• No protection is needed
• A steel nail plate at least 1/16 inch thick
• A plastic bushing at the hole entry
• Conduit must be used for all framing holes

NEC Reference: NEC 300.4(A)(1)

Question 21: How often must Type NM (Romex) cable be secured or supported along its run?

• Every 2 feet
• Every 4.5 feet
• Every 6 feet
• Every 10 feet

NEC Reference: NEC 334.30

Question 22: When an outlet box is installed in a combustible wall such as wood paneling, the box must be .............

• Set back at least 1/4 inch from the surface
• Flush with or projecting beyond the wall surface
• Set back at least 1/2 inch from the surface
• Position does not matter as long as cover plate fits

NEC Reference: NEC 314.20

Question 23: What is the minimum length required for a driven ground rod used as a grounding electrode?

• 4 feet
• 6 feet
• 8 feet
• 10 feet

NEC Reference: NEC 250.52(A)(5)(b)

Question 24: A motor controller must be rated for .............

• Half the circuit voltage
• At least the voltage of the circuit it controls
• Any voltage above 120V
• Only the motor horsepower, not voltage

NEC Reference: NEC 430.83

Question 25: How can the speed of a DC motor be controlled?

• Only by changing the supply frequency
• By adjusting the armature voltage or field current
• DC motors cannot have their speed changed
• Only by changing the number of poles

Question 26: Using Ohm's Law, if a circuit has 240V and 30 ohms of resistance, what is the current?

• 4 amperes
• 8 amperes
• 12 amperes
• 240 amperes

Question 27: In a wye (Y) connected 3-phase system, how does the line current compare to the phase current?

• Line current = √3 × phase current
• Line current = phase current
• Line current = phase current ÷ √3
• Line current = phase current × 3

Question 28: In a delta (Δ) connected 3-phase system, what is the relationship between line current and phase current?

• Line current = phase current
• Line current = phase current × √3
• Line current = phase current ÷ √3
• Line current = phase current × 3

Question 29: A motor takes in 5000 watts of electrical power and delivers 4000 watts of mechanical output. What is the motor efficiency?

• 60%
• 75%
• 80%
• 125%

Question 30: A transformer has a primary voltage of 480V and a turns ratio of 4:1 (primary to secondary). What is the secondary voltage?

• 1920 volts
• 240 volts
• 120 volts
• 48 volts