I85PREP
⌘ K
CITS Electrician (Theory) study materials
CITS Electrician (Theory) study resources

CITS Electrician (Theory) practice questions

One question at a time. Build your CITS Electrician (Theory) understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Electrical Safety and Codes

Under the Canadian Electrical Code, what is the maximum allowable current for a 15 A branch circuit that supplies only fixed baseboard heaters?

  1. 18 A
  2. 15 A
  3. 12 A Correct answer.
  4. 10 A

Explanation

Continuous heating loads are limited to 80 percent of the circuit rating, so a 15 A circuit may carry no more than 12 A of fixed heating load. The full 15 A rating is reserved for non-continuous loads.

Question 2Electrical Safety and Codes

Which conductor colour is used for the grounded (neutral) conductor in a typical Canadian branch circuit?

  1. Green
  2. Red
  3. Black
  4. White Correct answer.

Explanation

The neutral or grounded conductor is identified by white or natural grey insulation. Green is reserved for bonding conductors, and black and red are ungrounded (hot) conductors.

Question 3Electrical Safety and Codes

What is the primary purpose of bonding metal non-current-carrying parts of electrical equipment?

  1. To provide a return path for load current
  2. To balance the load across phases
  3. To ensure a low-impedance path that trips the overcurrent device during a fault Correct answer.
  4. To reduce voltage drop on long feeders

Explanation

Bonding creates a low-impedance fault path so that fault current is high enough to open the overcurrent protective device quickly. It does not carry load current and is not intended to improve voltage regulation.

Question 4Electrical Safety and Codes

A receptacle is installed within 1.5 m of a kitchen sink. What protection does the Canadian Electrical Code require for this receptacle?

  1. Arc fault circuit interrupter protection only
  2. A dedicated 20 A circuit
  3. Surge protection
  4. Ground fault circuit interrupter protection Correct answer.

Explanation

Receptacles near sinks and other wet locations must be protected by a ground fault circuit interrupter to reduce shock risk. AFCI protection addresses arc faults, not the shock hazard from contact with water.

Question 5Electrical Safety and Codes

What does the term 'ampacity' describe for a conductor?

  1. The maximum current the conductor can carry continuously under stated conditions Correct answer.
  2. The maximum voltage the insulation can withstand
  3. The resistance per unit length of the conductor
  4. The short-circuit withstand rating of the conductor

Explanation

Ampacity is the current-carrying capacity of a conductor under specified installation conditions without exceeding its temperature rating. It depends on conductor size, insulation type, and ambient conditions.

Question 6Electrical Safety and Codes

Which document in Canada provides the legal requirements for electrical installations that an electrician must follow?

  1. The Electrical Safety Authority Act
  2. The National Fire Code
  3. The National Building Code
  4. The Canadian Electrical Code, Part I Correct answer.

Explanation

The Canadian Electrical Code, Part I sets out the installation rules adopted into law by provincial and territorial regulations. Building, fire, and administrative statutes cover other aspects of construction and enforcement.

Question 7Electrical Safety and Codes

What is the minimum working clearance required in front of a residential electrical panel with no live parts on the opposite wall?

  1. 1.5 m
  2. 1 m Correct answer.
  3. 750 mm
  4. 500 mm

Explanation

A clear working space of at least 1 m must be maintained in front of electrical equipment to allow safe operation and maintenance. The space must extend from the floor to the required height and be kept unobstructed.

Question 8Electrical Safety and Codes

Which of the following is the correct action when a fuse repeatedly blows in a circuit?

  1. Determine and correct the cause of the overcurrent Correct answer.
  2. Replace the fuse with a copper jumper
  3. Bypass the fuse temporarily
  4. Install a fuse with a higher current rating

Explanation

A repeated fuse failure indicates a fault or overload that must be located and corrected. Increasing the fuse rating or bypassing it removes protection and creates a fire hazard.

Question 9Electrical Safety and Codes

A 240 V single-phase circuit draws 30 A. What is the minimum size of copper conductor with 60 °C insulation typically required if ampacity must be at least 30 A?

  1. No. 10 AWG Correct answer.
  2. No. 12 AWG
  3. No. 8 AWG
  4. No. 14 AWG

Explanation

At 60 °C, No. 10 AWG copper has an ampacity of 30 A, which matches the load requirement. No. 12 and No. 14 are rated at 20 A and 15 A respectively at that temperature.

Question 10Electrical Safety and Codes

A single-family dwelling has a 100 A service. Which condition requires that the service be increased?

  1. The panel has spare breaker spaces
  2. The homeowner plans to add a hot tub
  3. The service conductors are aluminum
  4. The calculated load exceeds 100 A Correct answer.

Explanation

Service size is governed by the calculated demand load; if that load exceeds the service rating, the service must be upgraded. Planned additions and conductor material alone do not determine adequacy.

Question 11Electrical Safety and Codes

What protection is required for a 20 A branch circuit supplying receptacles in a dwelling unit bedroom?

  1. Arc fault circuit interrupter protection Correct answer.
  2. Neither GFCI nor AFCI protection
  3. Both GFCI and AFCI protection in all cases
  4. Ground fault circuit interrupter protection

Explanation

Branch circuits supplying receptacles in dwelling unit bedrooms require arc fault circuit interrupter protection to reduce fire risk from arcing faults. GFCI protection applies to specific wet or high-risk locations, not all bedroom receptacles.

Question 12Electrical Safety and Codes

A 120 V load of 12 A is located 30 m from the panel using No. 12 AWG copper conductors with a total circuit resistance of 1.2 Ω. What is the approximate voltage drop?

  1. 0.72 V
  2. 7.2 V
  3. 14.4 V Correct answer.
  4. 1.44 V

Explanation

Voltage drop equals current times total conductor resistance, so 12 A × 1.2 Ω = 14.4 V. This exceeds the commonly recommended 3 percent limit for branch circuits and suggests upsizing the conductors.

Question 13Electrical Safety and Codes

Which wiring method is generally acceptable for exposed work in a dry, accessible location such as a garage?

  1. Non-metallic sheathed cable in wet locations
  2. Armoured cable Correct answer.
  3. Loose conductors in a raceway without fittings
  4. Flexible cord as permanent wiring

Explanation

Armoured cable is permitted for exposed work in dry locations and provides mechanical protection. Flexible cord and loose conductors without proper fittings are not acceptable as permanent wiring.

Question 14Electrical Safety and Codes

What is the purpose of a disconnecting means at service equipment?

  1. To limit voltage to 120 V
  2. To isolate the service from all supply conductors for maintenance Correct answer.
  3. To balance phase currents
  4. To protect against arc faults

Explanation

The service disconnecting means allows the entire installation to be isolated from the supply for safe maintenance and emergencies. It must be readily accessible and clearly marked.

Question 15Electrical Safety and Codes

How many 20 A general-purpose receptacle circuits are typically required for a 150 m² dwelling unit under the code minimum?

  1. At least one 20 A circuit
  2. No minimum applies
  3. At least four 20 A circuits
  4. At least two 20 A circuits Correct answer.

Explanation

Dwelling units require at least two 20 A small-appliance branch circuits for kitchen and general-purpose receptacles. Additional circuits may be needed based on calculated load and layout.

Question 16Electrical Safety and Codes

A panelboard is installed in a bathroom. Which statement best describes the code requirement?

  1. It is permitted if the panel is GFCI protected
  2. It is permitted if it is mounted above the sink
  3. It is not permitted in a bathroom Correct answer.
  4. It is permitted only in commercial bathrooms

Explanation

Overcurrent devices are not permitted in bathrooms because of the shock hazard and moisture. GFCI protection or mounting location does not make a bathroom an acceptable panel location.

Question 17Electrical Safety and Codes

What is the minimum burial depth for direct-buried non-metallic sheathed cable supplying a residential outbuilding where it crosses under a lawn?

  1. 450 mm Correct answer.
  2. 300 mm
  3. 1 m
  4. 600 mm

Explanation

Direct-buried cable under a lawn requires a minimum cover of 450 mm without additional protection. Greater depths apply under driveways or where mechanical protection is absent.

Question 18Electrical Safety and Codes

A motor circuit has a full-load current of 25 A. What is the maximum rating of the overload protection device typically permitted for a continuous-duty motor?

  1. 50 A
  2. 31.25 A Correct answer.
  3. 37.5 A
  4. 25 A

Explanation

Motor overload protection is generally sized at up to 125 percent of full-load current, giving 31.25 A here. This allows for starting and normal operating variations without nuisance tripping.

Question 19Electrical Safety and Codes

Which of the following best describes the role of the Canadian Electrical Code in relation to provincial law?

  1. It replaces provincial regulations entirely
  2. It applies only to commercial installations
  3. It is advisory only and cannot be enforced
  4. It is adopted by provincial regulation and enforced by the authority having jurisdiction Correct answer.

Explanation

The Canadian Electrical Code becomes legally binding when adopted by provincial or territorial regulation and is enforced by the authority having jurisdiction. It does not replace local regulations but operates through them.

Question 20Electrical Safety and Codes

A 200 A service supplies a dwelling with a calculated load of 180 A. What is the minimum standard service rating that satisfies the load?

  1. 200 A Correct answer.
  2. 150 A
  3. 100 A
  4. 225 A

Explanation

The service rating must be at least equal to the calculated load, and standard ratings are used. A 200 A service satisfies the 180 A calculated load without exceeding the next standard size.

Question 21Electrical Safety and Codes

What is the primary function of a ground fault circuit interrupter in a circuit?

  1. It reduces voltage transients on the circuit
  2. It prevents arc faults in damaged conductors
  3. It limits the total current to the circuit rating
  4. It detects a difference between line and neutral current and opens the circuit Correct answer.

Explanation

A GFCI monitors the current in the line and neutral conductors and trips when the difference indicates current leaking to ground. This protects people from electric shock.

Question 22Electrical Safety and Codes

A conductor is installed in an ambient temperature of 40 °C instead of the 30 °C assumed for its ampacity rating. What effect does this have on the allowable current?

  1. The ampacity doubles to compensate
  2. The ampacity decreases because the allowable temperature rise is reduced Correct answer.
  3. The ampacity is unchanged because insulation rating is fixed
  4. The ampacity increases because heat dissipates faster

Explanation

Higher ambient temperature reduces the temperature rise the conductor can tolerate before reaching its insulation limit, so a correction factor lowers ampacity. This prevents overheating and insulation damage.

Question 23Electrical Safety and Codes

Which condition would require a bonding conductor to be installed between metallic water piping and the electrical system?

  1. The piping is entirely plastic
  2. The piping is used only for irrigation
  3. The piping is buried below the frost line
  4. The piping is metallic and likely to become energized Correct answer.

Explanation

Metallic water piping that may become energized must be bonded to the grounding system to ensure a low-impedance fault path. Plastic piping is non-conductive and does not require bonding.

Question 24Electrical Safety and Codes

A 3-phase, 4-wire feeder supplies a panel with a mix of line-to-neutral loads. What is the primary concern when balancing these loads?

  1. Excessive grounding conductor current
  2. Reduced insulation resistance
  3. Increased arc fault risk
  4. Excessive neutral current and voltage imbalance Correct answer.

Explanation

Unbalanced line-to-neutral loads cause current to flow in the neutral and can produce voltage imbalance between phases. Balancing the loads reduces neutral current and improves voltage stability.

Question 25Electrical Safety and Codes

A circuit breaker with a 10 kA interrupting rating is installed where the available fault current is 15 kA. What is the consequence?

  1. The breaker rating increases automatically
  2. The breaker will trip faster than rated
  3. The breaker will safely interrupt the fault
  4. The breaker may fail to interrupt the fault safely Correct answer.

Explanation

A breaker must have an interrupting rating at least equal to the available fault current. If the available fault current exceeds the rating, the device may not safely clear the fault.

Question 26Electrical Safety and Codes

In a Canadian electrical installation, which class of bonding conductor is intended to carry fault current only for the duration of a fault, and therefore may be sized smaller than the circuit conductors it serves?

  1. The bonding conductor around a water meter
  2. The grounding electrode conductor to the water pipe
  3. The equipment bonding conductor run with the branch circuit Correct answer.
  4. The system bonding jumper at the service

Explanation

An equipment bonding conductor provides a low-impedance fault-current path from exposed metal parts back to the source, so it only carries current during a fault. Because it is not a normal current-carrying conductor, the code permits it to be sized from a table based on the rating of the overcurrent device rather than matching the phase conductors.

Question 27Electrical Safety and Codes

A split-system air conditioner unit sits on a rooftop of a commercial building. Which statement best describes the code requirement for a disconnecting means at the unit?

  1. The panelboard breaker in the electrical room is always accepted as the unit disconnect
  2. A disconnect is required only when the unit exceeds 5 kW
  3. A disconnecting means must be within sight of and readily accessible from the unit Correct answer.
  4. No disconnecting means is required because the rooftop is not accessible to the public

Explanation

Motor-driven appliances such as air conditioners require a disconnecting means that is within sight of and readily accessible from the equipment so a person servicing it can open the circuit and keep it visible. The branch-circuit breaker in a remote electrical room does not satisfy this because it cannot be seen from the unit.

Question 28Electrical Safety and Codes

A 15 A branch circuit supplies a receptacle in an unfinished basement of a dwelling unit. Which protective measure does the Canadian Electrical Code require for this receptacle?

  1. Class A ground fault circuit interrupter protection Correct answer.
  2. A combination AFCI and GFCI device rated at 30 mA
  3. Neither GFCI nor AFCI protection, because the load is not in a wet location
  4. Arc fault circuit interrupter protection only

Explanation

Receptacles in dwelling-unit locations such as unfinished basements, garages, bathrooms, and outdoors require Class A ground fault circuit interrupter protection because of the increased shock risk from dampness and contact with earth or masonry. Class A devices trip in the 4 to 6 mA range, which is the level associated with protection of persons.

Question 29Electrical Safety and Codes

A feeder passes through a metal stud wall and the conductors are run in flexible metal conduit. What is the purpose of bonding the flexible metal conduit at both ends of the run?

  1. To ensure the conduit jacket remains a low-impedance fault-current path along the whole length Correct answer.
  2. To reduce induced voltages caused by the conductors inside the conduit
  3. To provide the grounding electrode connection for the building
  4. To prevent the conduit from acting as a parallel neutral path

Explanation

Flexible metal conduit is a metallic raceway that can become energized if a conductor inside faults to it, so it must be bonded to provide a continuous low-impedance path back to the source. Bonding at both ends keeps the raceway at earth potential and lets the overcurrent device open quickly during a fault.

Question 30Electrical Safety and Codes

A service is supplied by a 120/240 V single-phase system with a 200 A service disconnect. The electrician proposes to install the grounding electrode conductor to a driven rod electrode. Which consideration governs the minimum size of that conductor?

  1. It must always match the service conductor size exactly
  2. It is sized from the service conductor ampacity, but is not required to be larger than No. 6 AWG copper for a rod electrode Correct answer.
  3. It is sized from the rating of the largest branch-circuit breaker in the panel
  4. It may be any size because a rod electrode has high resistance

Explanation

The grounding electrode conductor is sized from the service or feeder conductor ampacity using the code table, but a limit applies when the sole electrode is a rod, pipe, or plate electrode, so the conductor need not exceed a stated maximum size. This recognizes that a single rod has limited ability to carry current to earth.

Question 31Electrical Theory and Fundamentals

In a purely resistive AC circuit, what is the phase relationship between the applied voltage and the current?

  1. Current leads voltage by 45 degrees
  2. Current leads voltage by 90 degrees
  3. Voltage and current are exactly in phase Correct answer.
  4. Voltage leads current by 90 degrees

Explanation

In a resistance the voltage across it and the current through it rise and fall together, so the phase angle is zero. Power is always positive and equals V times I at every instant. Phase shifts arise only from reactive elements such as inductors and capacitors.

Question 32Electrical Theory and Fundamentals

A coil draws 0.5 A when connected across a 240 V supply. What is its resistance, assuming it is the only limiting element?

  1. 480 ohms Correct answer.
  2. 120 ohms
  3. 48 ohms
  4. 240 ohms

Explanation

Ohm's law gives R = V / I, so 240 divided by 0.5 equals 480 ohms. The resistance is the ratio of voltage across the element to the current through it. Multiplying instead of dividing is the usual error here.

Question 33Electrical Theory and Fundamentals

Which unit correctly expresses electrical power in a DC circuit?

  1. The farad
  2. The watt Correct answer.
  3. The coulomb
  4. The joule

Explanation

Power is the rate of energy transfer, measured in watts, where one watt is one joule per second. In DC circuits power equals voltage multiplied by current. The joule measures energy, the coulomb measures charge and the farad measures capacitance.

Question 34Electrical Theory and Fundamentals

Two resistors of 6 ohms and 3 ohms are connected in parallel. What is the equivalent resistance?

  1. 1.5 ohms
  2. 9 ohms
  3. 2 ohms Correct answer.
  4. 4.5 ohms

Explanation

For two parallel resistors the product over sum rule applies: (6 x 3) / (6 + 3) = 18 / 9 = 2 ohms. The equivalent is always smaller than the smallest branch resistance. Adding the values would only be correct for a series connection.

Question 35Electrical Theory and Fundamentals

What is the principal hazard of electric current passing through the human body?

  1. It can disrupt the heart rhythm and cause burns Correct answer.
  2. It always improves blood circulation
  3. It only causes a harmless tingling sensation
  4. It has no effect below 500 V

Explanation

Body current can cause ventricular fibrillation, muscle contraction and internal or external burns. Even small currents passing through the chest for a sufficient time can be fatal. The severity depends on current magnitude, path and duration rather than voltage alone.

Question 36Electrical Theory and Fundamentals

Which material is classified as an electrical insulator?

  1. Silver
  2. Copper
  3. Rubber Correct answer.
  4. Aluminium

Explanation

Insulators hold electrons tightly, so very little current flows when a voltage is applied; rubber is used to sheath conductors for this reason. Copper, aluminium and silver are metals with abundant free electrons and low resistivity. Insulation resistance falls if the material becomes wet or contaminated.

Question 37Electrical Theory and Fundamentals

What is the frequency of a supply whose period is 20 milliseconds?

  1. 60 Hz
  2. 50 Hz Correct answer.
  3. 200 Hz
  4. 20 Hz

Explanation

Frequency is the reciprocal of the period, so f = 1 / 0.020 s = 50 Hz. A 20 ms period corresponds to one complete cycle of a 50 Hz waveform. This matches common European and Australian mains frequency.

Question 38Electrical Theory and Fundamentals

Which statement describes the function of a fuse in a circuit?

  1. It converts alternating current into direct current
  2. It opens the circuit when current exceeds its rating Correct answer.
  3. It limits the current by adding reactance
  4. It stores energy for later release

Explanation

A fuse contains a calibrated element that melts when the current exceeds its rating, breaking the circuit and protecting conductors and equipment. It is a one-shot device that must be replaced after operation. It does not regulate current or convert supply type.

Question 39Electrical Theory and Fundamentals

A 12 V battery delivers 3 A to a load. How much power is dissipated in the load?

  1. 15 W
  2. 4 W
  3. 36 W Correct answer.
  4. 0.25 W

Explanation

DC power equals voltage multiplied by current: 12 V x 3 A = 36 W. The same result follows from I squared R once the resistance is known. Dividing voltage by current gives resistance, not power.

Question 40Electrical Theory and Fundamentals

Three 12 ohm resistors are connected in parallel. What is the total resistance?

  1. 6 ohms
  2. 12 ohms
  3. 36 ohms
  4. 4 ohms Correct answer.

Explanation

For n equal resistors in parallel the equivalent is R divided by n, so 12 / 3 = 4 ohms. Each branch carries one third of the total current. Connecting in series would instead give 36 ohms.

Question 41Electrical Theory and Fundamentals

In a series circuit containing a resistor and an inductor, how does the total voltage relate to the component voltages?

  1. It equals the arithmetic sum of the two voltages
  2. It equals the phasor sum of the two voltages Correct answer.
  3. It is always equal to the resistor voltage
  4. It equals the difference of the two voltages

Explanation

The resistor voltage is in phase with the current while the inductor voltage leads by 90 degrees, so the two are added as phasors. The supply voltage is the vector sum and its magnitude is the square root of the sum of the squares. Simple addition is valid only when the voltages are in phase.

Question 42Electrical Theory and Fundamentals

What is the capacitive reactance of a 100 microfarad capacitor at 50 Hz, to the nearest ohm?

  1. 3183 ohms
  2. 32 ohms Correct answer.
  3. 314 ohms
  4. 50 ohms

Explanation

Capacitive reactance is Xc = 1 / (2 pi f C). Here 2 pi x 50 x 0.0001 equals about 0.0314, and its reciprocal is roughly 31.8 ohms, rounding to 32 ohms. Reactance falls as frequency or capacitance increases.

Question 43Electrical Theory and Fundamentals

A transformer has 500 primary turns and 100 secondary turns. If the primary is supplied at 240 V, what is the secondary voltage?

  1. 24 V
  2. 1200 V
  3. 48 V Correct answer.
  4. 240 V

Explanation

The turns ratio equals the voltage ratio, so the secondary voltage is 240 V x (100 / 500) = 48 V. A step-down ratio of five to one halves nothing; it divides the voltage by five. Transformers transfer power, so the secondary current rises in the same proportion.

Question 44Electrical Theory and Fundamentals

Which rule determines the direction of the magnetic field around a current-carrying conductor?

  1. The right-hand grip rule Correct answer.
  2. The left-hand rule for motors
  3. The potential divider rule
  4. Faraday's law

Explanation

The right-hand grip rule states that if the thumb points along the conventional current, the curled fingers show the direction of the magnetic field. The field forms concentric circles around a straight conductor. Faraday's law concerns induced EMF rather than field direction.

Question 45Electrical Theory and Fundamentals

A single-phase load of 2 kW operates at 230 V with a power factor of 0.8. What is the current drawn, to the nearest tenth of an ampere?

  1. 10.9 A Correct answer.
  2. 12.5 A
  3. 8.7 A
  4. 15.0 A

Explanation

For single-phase AC, I = P / (V x power factor). Substituting gives 2000 / (230 x 0.8) = 2000 / 184, which is about 10.9 A. Ignoring the power factor understates the current and can lead to undersized cables.

Question 46Electrical Theory and Fundamentals

What happens to the total resistance of a circuit as more resistors are added in parallel?

  1. It increases proportionally to the number added
  2. It decreases Correct answer.
  3. It remains constant
  4. It becomes infinite

Explanation

Each parallel branch provides an additional path for current, so the total conductance rises and the equivalent resistance falls. The equivalent is always less than the smallest individual branch resistance. This is why adding loads to a domestic installation increases total current.

Question 47Electrical Theory and Fundamentals

In a three-phase star-connected system with a line voltage of 400 V, what is the phase voltage to the nearest volt?

  1. 565 V
  2. 231 V Correct answer.
  3. 693 V
  4. 400 V

Explanation

In a star connection the phase voltage is the line voltage divided by the square root of three. Dividing 400 by 1.732 gives approximately 231 V. The line current equals the phase current in a star connection.

Question 48Electrical Theory and Fundamentals

A resistor of 10 ohms carries a current of 2 A. What power does it dissipate?

  1. 80 W
  2. 20 W
  3. 5 W
  4. 40 W Correct answer.

Explanation

Using P = I squared R gives 2 squared x 10 = 4 x 10 = 40 W. The same answer follows from first finding the voltage drop of 20 V and multiplying by 2 A. Using I x R alone gives voltage, not power.

Question 49Electrical Theory and Fundamentals

Which statement about the voltage in a series circuit is correct?

  1. The voltage is the same across every component
  2. The voltage is zero across the largest resistance
  3. The total voltage equals the largest component voltage
  4. The supply voltage divides across the components in proportion to their resistance Correct answer.

Explanation

In a series circuit the current is common to all components, so the voltage divides in proportion to resistance according to V = IR. The sum of the component voltages equals the supply voltage. The largest resistance therefore drops the largest voltage.

Question 50Electrical Theory and Fundamentals

A 24 V DC source is connected across a potential divider of 8 ohms and 16 ohms in series. What is the voltage across the 16 ohm resistor?

  1. 24 V
  2. 16 V Correct answer.
  3. 12 V
  4. 8 V

Explanation

The total resistance is 24 ohms, so the current is 24 / 24 = 1 A. The voltage across the 16 ohm resistor is then 1 A x 16 ohms = 16 V. The divider splits the supply in the ratio of the resistances.