Question 1
What is the standard nominal single-phase service voltage supplied to most Canadian dwellings?
Question 2
A 1500 W baseboard heater is connected to a 120 V circuit. Approximately how much current does it draw?
Question 3
A 120 V, 15 A general-use branch circuit supplies twelve receptacles in a room. Each connected load draws about 1.5 A when in use. What is the main concern if all twelve loads operate simultaneously?
Question 4
A 120 V branch circuit supplies a continuous load of 12 A in a commercial occupancy. Which breaker size is most appropriate, considering typical continuous load requirements?
Question 5
A 5 kW, 240 V single-phase motor has a power factor close to 1. Approximately what full-load current would you expect?
Question 6
Two 60 W, 120 V lamps are connected in parallel on a 120 V circuit. What is the total current drawn by the two lamps?
Question 7
A panel schedule shows a 2-pole 30 A breaker feeding a 240 V water heater. What information does this provide to the electrician?
Question 8
A standard receptacle circuit in a Canadian dwelling is typically supplied at which nominal voltage?
Question 9
On a panel schedule, a circuit is labelled '2P-30 A, Dryer'. What does this indicate?
Question 10
A three-phase, 4-wire, 120/208 V system supplies a group of lighting loads connected line-to-neutral. What is the line-to-line voltage on this system?
Question 11
A residential kitchen requires at least two small-appliance branch circuits. Each is 20 A at 120 V. What is the combined kVA rating of these two circuits assuming they are fully loaded?
Question 12
A standard duplex receptacle in a Canadian dwelling is typically rated at:
Question 13
What is the typical nominal voltage between a single hot conductor and neutral in a Canadian residential system?
Question 14
A feeder conductor is loaded to 40 A and has a resistance of 0.25 Ω for the round-trip length. What is the voltage drop on this feeder?
Question 15
You are connecting a 9 kW, 240 V single-phase water heater. Assuming 100% load and using a 125% factor for continuous operation, approximately what current must the branch circuit be designed to carry?
Question 16
A 480 V:120/240 V transformer supplies a dwelling panelboard. If the primary draws 25 A at 480 V, ignoring losses, what is the approximate full-load current on the 120/240 V secondary?
Question 17
A general-use 120 V branch circuit in a dwelling is rated at 20 A. Which copper conductor size is typically the minimum acceptable for this circuit under standard conditions?
Question 18
A 120 V circuit supplies a 60 W incandescent lamp. Approximately how much current does the lamp draw?
Question 19
An electric heater is rated at 1500 W on a 120 V circuit. Approximately what current does it draw?
Question 20
You are asked to install a 30 A, 240 V single-phase circuit for a water heater. Which common two-pole breaker type is appropriate?
Question 21
On a typical Canadian residential branch circuit, what is the nominal voltage at a standard duplex receptacle?
Question 22
A 120 V circuit supplies a 12 Ω resistive load. What is the current flowing in the circuit?
Question 23
A 1500 W heater is connected to a 120 V branch circuit. Approximately how much current does the heater draw?
Question 24
A 60 W, 120 V incandescent lamp is connected to a 120 V supply. Approximately how much current does it draw?
Question 25
A 120 V branch circuit supplies three loads connected in parallel: 300 W, 600 W, and 150 W. What is the total current drawn by the circuit?
Question 26
You are asked to install a receptacle for a clothes dryer that requires a 30 A, 240 V supply in a Canadian dwelling. Which common cable size and type would typically be suitable for this circuit, assuming a standard installation in dry locations?
Question 27
A contactor coil is rated 120 V AC and is controlled by a pilot device. What will happen if the coil is connected to 240 V AC by mistake?
Question 28
A 10 Ω resistor and a 20 Ω resistor are connected in series across a 120 V supply. What is the voltage drop across the 20 Ω resistor?
Question 29
Which of the following is a typical voltage for general-purpose branch circuits in Canadian dwelling units?
Question 30
A contactor coil is rated 120 V AC, but the control transformer secondary is 24 V AC. Which is the best solution?