Question 31
Before beginning work on a branch circuit that has been switched off at the breaker, what is the next safe step an apprentice should take?
Question 32
An apprentice is asked to calculate the total load on a 120 V branch circuit supplying six receptacles, each assumed at 180 VA. What is the total assumed load?
Question 33
Before starting work on a residential branch circuit, what is the first safety step an apprentice electrician should take?
Question 34
In a typical Canadian dwelling unit, what is the standard rating for general-purpose 120 V branch circuit breakers supplying receptacles?
Question 35
A single-phase, 240 V motor has a nameplate full-load current of 12 A. Which branch-circuit conductor ampacity is most appropriate, assuming typical Canadian code rules for motor circuits?
Question 36
In a commercial building, which practice is typically required for circuits supplying emergency lighting?
Question 37
A 15 A, 120 V general-purpose branch circuit in a dwelling supplies eight duplex receptacles. Which statement best reflects good practice for loading this circuit?
Question 38
A multi-wire branch circuit supplies two small appliance circuits in a kitchen using a shared neutral. One pole of the two-pole breaker is turned off while the other remains on, and the neutral connection at a junction box becomes loose. Which hazard can result from this situation?
Question 39
Which instrument is most appropriate for safely verifying that a 120 V branch circuit is de-energized before beginning work?
Question 40
What is the nominal voltage between a hot conductor and neutral on a typical single-phase residential branch circuit in Canada?
Question 41
Before energizing a new branch circuit, a continuity test is performed between the equipment bonding conductor and metal boxes. What does a successful test indicate?
Question 42
A 120 V branch circuit supplies a 12 A load over a long run. If the total circuit resistance of the conductors is 0.8 Ω, what is the approximate voltage at the load?
Question 43
A multiwire branch circuit in a dwelling uses two ungrounded conductors sharing a neutral on a common cable. Which condition must be met to ensure the neutral is not overloaded?
Question 44
Which instrument should an electrician use to safely measure voltage in a live branch circuit?
Question 45
In a standard 120 V branch circuit with a separate bonding conductor, how many conductors are required in the cable or conduit?
Question 46
A 15 A general-use branch circuit is repeatedly tripping the breaker when a portable heater is plugged in. The heater is marked 1500 W at 120 V. Which is the best explanation?
Question 47
A 20 A, 120 V branch circuit is being installed for receptacles in a Canadian dwelling. Which copper conductor size is typically required?
Question 48
After a bathroom renovation, none of the receptacles in the bathroom work, but the breaker in the panel is not tripped. What should the electrician check first?
Question 49
In a multiwire branch circuit with two ungrounded conductors sharing a neutral, what hazard can occur if the shared neutral is disconnected while the circuit is energized?
Question 50
An electrician measures 120 V at a receptacle, but a plugged-in lamp does not operate. The lamp is known to be good. Which is the most appropriate next step?
Question 51
What is the maximum number of outlets permitted on a 15A branch circuit in a residential dwelling according to general CEC rules?
Question 52
Which device is used to protect conductors from overcurrent conditions in a branch circuit?
Question 53
You are installing a 15 A general-purpose branch circuit in a Canadian dwelling unit. Which conductor size is typically used for this circuit, subject to code requirements?
Question 54
You are asked to add a receptacle circuit in an unfinished basement area of a dwelling. Which of the following code-related considerations is most important?
Question 55
A grounded receptacle tester shows an open ground indication on a receptacle. What is the most appropriate first step?
Question 56
In a Canadian dwelling unit, which location typically requires GFCI protection?
Question 57
In a Canadian dwelling, which location clearly requires a GFCI-protected receptacle?
Question 58
You are asked to install a 20 A, 120 V branch circuit for receptacles in a workshop. Which copper conductor size and overcurrent device rating combination is most appropriate?
Question 59
A receptacle in a washroom is dead, but the breaker is not tripped. Other receptacles on the same circuit in dry locations are also dead. What is the most likely cause?
Question 60
A 120 V branch circuit supplies a 600 W heater. What is the approximate current on the circuit, and which overcurrent device rating is most appropriate (ignoring continuous load rules for this question)?