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BTEB Electrician (EIM) Exam study materials
BTEB Electrician (EIM) Exam study resources

BTEB Electrician (EIM) Exam practice questions

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Question 1Occupational Health, Safety and Environment

Which colour identifies a safety sign that indicates a mandatory action, such as wearing eye protection?

  1. Yellow
  2. Green
  3. Red
  4. Blue Correct answer.

Explanation

Mandatory signs use a blue circular background with a white symbol, so blue is the recognised colour for actions that must be carried out. Red is reserved for prohibition and fire equipment, yellow for warning, and green for safe conditions or escape routes.

Question 2Occupational Health, Safety and Environment

A workshop has a fire involving energised electrical equipment. Which extinguisher medium is appropriate for attacking this fire?

  1. Foam
  2. Carbon dioxide Correct answer.
  3. Water under pressure
  4. Wet sand

Explanation

Carbon dioxide is non-conductive and leaves no residue, so it can be discharged onto live electrical equipment by a trained person. Water, foam, and wet sand all conduct electricity and create a shock risk to the operator.

Question 3Occupational Health, Safety and Environment

What is the main purpose of a residual current device in a portable tool circuit?

  1. To protect against electric shock Correct answer.
  2. To raise the supply voltage
  3. To reduce energy consumption
  4. To limit the motor speed

Explanation

A residual current device continuously compares the current in the live and neutral conductors and trips when a small imbalance indicates leakage to earth. This rapid disconnection limits the duration of a shock and reduces the chance of fatal injury.

Question 4Occupational Health, Safety and Environment

Which practice best prevents the spread of hand-to-hand infection among workers sharing hand tools?

  1. Storing tools in an open box
  2. Wearing gloves only in cold weather
  3. Wiping tools with a dry cloth
  4. Washing hands before breaks and after work Correct answer.

Explanation

Regular hand washing with soap and water removes transient microorganisms picked up from shared surfaces and tools. It is the single most effective routine measure for interrupting contact transmission in a workshop.

Question 5Occupational Health, Safety and Environment

Which item of personal protective equipment is essential when drilling overhead into concrete?

  1. Steel-toe boots
  2. Knee pads
  3. Safety goggles Correct answer.
  4. Ear defenders

Explanation

Overhead drilling releases dust and chips that fall towards the face, so eye protection is the primary control. Safety goggles seal against the face and resist impact and fine particles better than spectacles.

Question 6Occupational Health, Safety and Environment

A worker must isolate a circuit before maintenance. Which sequence follows safe isolation practice?

  1. Test dead, isolate, work, then lock off
  2. Isolate, lock off, prove the tester, test dead, then work Correct answer.
  3. Lock off, work, then test dead
  4. Prove the tester, work, then isolate

Explanation

Safe isolation requires switching off and locking the device, proving the voltage tester on a known source, then proving the circuit dead at the point of work. Locking before testing prevents accidental re-energisation while the checks are made.

Question 7Occupational Health, Safety and Environment

Why is a portable electrical tool with a damaged outer sheath of its flexible cord taken out of service immediately?

  1. It may expose live conductors to touch Correct answer.
  2. It may overheat and slow the motor
  3. It may void the manufacturer's paint finish
  4. It may increase the tool's torque

Explanation

A damaged sheath removes the insulation barrier, so a live conductor can be contacted directly or become live metalwork through moisture. The tool must be withdrawn and repaired before further use.

Question 8Occupational Health, Safety and Environment

A ladder is used for short-duration work at height. Which practice meets the general safety requirement?

  1. Standing on the top two rungs
  2. Carrying a heavy load in both hands
  3. Facing away from the ladder while descending
  4. Leaning the ladder at about 75 degrees Correct answer.

Explanation

A ladder set at roughly 75 degrees, or one unit out for every four units up, gives a stable angle that resists slipping. The user should keep three points of contact and avoid the top rungs.

Question 9Occupational Health, Safety and Environment

Which control measure ranks highest in the hierarchy of risk control for a noisy grinding operation?

  1. Enclosing the machine to reduce noise at source Correct answer.
  2. Limiting exposure to two hours per shift
  3. Issuing ear plugs to operators
  4. Posting a warning sign at the entrance

Explanation

The hierarchy places elimination and engineering controls above administrative measures and personal protective equipment. Enclosing or silencing the machine removes noise at source and protects everyone nearby, not just the wearer.

Question 10Occupational Health, Safety and Environment

A worker contacts a live conductor and cannot let go. What should a rescuer do first?

  1. Wait for the worker to fall free
  2. Switch off the supply or isolate the circuit Correct answer.
  3. Throw water on the worker
  4. Pull the worker away by the arm

Explanation

The supply must be interrupted before anyone touches the casualty, otherwise the rescuer becomes a second victim. Only if isolation is impossible should insulated material be used to separate the person from the conductor.

Question 11Occupational Health, Safety and Environment

Which statement correctly describes the action of a fuse in a circuit?

  1. It reduces the voltage supplied to the load
  2. It melts and opens the circuit when current exceeds its rating Correct answer.
  3. It limits the current by adding resistance in normal use
  4. It restores supply automatically after a fault

Explanation

A fuse contains a element that is designed to melt when the current exceeds its rating for a sufficient time, thereby opening the circuit. It protects conductors and equipment from overheating caused by overload or fault current.

Question 12Occupational Health, Safety and Environment

Which precaution applies when a worker must enter a confined space such as a cable chamber?

  1. Rely on a nose test to detect toxic gas
  2. Test the atmosphere before entry and provide a standby person Correct answer.
  3. Enter alone to keep the team small
  4. Leave the access cover closed during the work

Explanation

Confined spaces may contain oxygen deficiency or toxic or flammable gas, so the atmosphere must be tested before and during entry. A standby person outside maintains communication and can raise the alarm or assist without entering.

Question 13Occupational Health, Safety and Environment

A supervisor is planning work near an overhead line. Which measure is the most reliable way to control the risk?

  1. Telling workers to be careful near the line
  2. Scheduling the work for early morning
  3. Erecting a warning sign beneath the line
  4. Arranging with the network operator to isolate or divert the line Correct answer.

Explanation

Eliminating the hazard by having the line made dead or diverted removes the risk entirely and is the preferred control. Warnings and scheduling are administrative measures that leave the live conductor in place.

Question 14Occupational Health, Safety and Environment

During a risk assessment, a task is rated as high risk with severe consequences. What does the principle of ALARP require?

  1. Transferring the risk to the client by contract
  2. Accepting the risk because the task must be done
  3. Reducing risk until the cost of further control exceeds the benefit Correct answer.
  4. Reducing risk only until a written record exists

Explanation

ALARP means reducing risk as low as reasonably practicable, weighing the sacrifice of further control against the reduction in risk achieved. Grossly disproportionate cost can justify stopping, but trivial or administrative measures are expected first.

Question 15Occupational Health, Safety and Environment

A portable appliance test shows a low insulation resistance reading on a Class I tool. What is the correct interpretation?

  1. The tool should be used only on a longer lead
  2. The tool must be withdrawn and investigated before use Correct answer.
  3. The tool is safe because the earth continuity passed
  4. The reading is normal for all Class I tools

Explanation

A low insulation resistance indicates possible moisture, contamination, or breakdown of insulation between live parts and the earthed frame. The tool should be removed from service and fault-found rather than returned to use on the strength of another test.

Question 16Occupational Health, Safety and Environment

Which combination correctly matches a hazard to its most appropriate first-line control?

  1. Dust to a warning sign
  2. Flying particles to machine guarding Correct answer.
  3. Noise to reduced working hours
  4. Vibration to thicker gloves

Explanation

Machine guarding is an engineering control that physically contains flying particles at source, which ranks above administrative and personal measures. The other pairings rely on measures lower in the hierarchy or on controls that do not address the hazard.

Question 17Basic Electrical Principles and Calculations

Which quantity is defined as the rate of flow of electric charge past a point in a circuit?

  1. Resistance
  2. Power
  3. Electromotive force
  4. Electric current Correct answer.

Explanation

Electric current is the rate at which charge passes a point, measured in amperes where one ampere equals one coulomb per second. It describes movement of charge rather than the energy given to that charge.

Question 18Basic Electrical Principles and Calculations

A resistor of 12 ohms carries a current of 0.5 A. What is the voltage across it?

  1. 24 V
  2. 0.042 V
  3. 12.5 V
  4. 6 V Correct answer.

Explanation

Ohm's law states that voltage equals current multiplied by resistance. Multiplying 0.5 A by 12 ohms gives 6 V across the resistor.

Question 19Basic Electrical Principles and Calculations

What is the unit of electrical resistance?

  1. Watt
  2. Ampere
  3. Ohm Correct answer.
  4. Volt

Explanation

Resistance is measured in ohms, symbol omega. One ohm is the resistance that allows one ampere to flow when one volt is applied across it.

Question 20Basic Electrical Principles and Calculations

A 60 W lamp operates on a 240 V supply. What current does it draw?

  1. 0.25 A Correct answer.
  2. 0.5 A
  3. 14 400 A
  4. 4 A

Explanation

Power equals voltage multiplied by current, so current equals power divided by voltage. Dividing 60 W by 240 V gives 0.25 A.

Question 21Basic Electrical Principles and Calculations

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

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

Explanation

In a purely resistive circuit the current rises and falls at the same instants as the voltage, so the phase difference is zero. The 90-degree shifts occur only with pure inductance or pure capacitance.

Question 22Basic Electrical Principles and Calculations

Which material is classified as a good electrical conductor?

  1. Copper Correct answer.
  2. Dry wood
  3. Glass
  4. Rubber

Explanation

Copper has loosely bound outer electrons that move freely under an applied voltage, giving it low resistivity. This is why it is widely used for conductors in wiring and cables.

Question 23Basic Electrical Principles and Calculations

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

  1. 18 ohms
  2. 2 ohms Correct answer.
  3. 9 ohms
  4. 4.5 ohms

Explanation

For two resistors in parallel the equivalent resistance is the product divided by the sum, so 6 times 3 divided by 9 gives 2 ohms. The result must always be smaller than the smallest branch resistance.

Question 24Basic Electrical Principles and Calculations

A charge of 30 coulombs flows through a conductor in 10 seconds. What is the current?

  1. 300 A
  2. 3 A Correct answer.
  3. 30 A
  4. 0.33 A

Explanation

Current equals charge divided by time. Dividing 30 coulombs by 10 seconds gives 3 amperes.

Question 25Basic Electrical Principles and Calculations

A 12 V battery delivers 2 A to a circuit. What power is delivered?

  1. 0.167 W
  2. 14 W
  3. 6 W
  4. 24 W Correct answer.

Explanation

Electrical power is the product of voltage and current. Multiplying 12 V by 2 A gives 24 W.

Question 26Basic Electrical Principles and Calculations

A heater rated 2 kW runs for 3 hours. How much electrical energy does it consume in kilowatt-hours?

  1. 0.67 kWh
  2. 5 kWh
  3. 6000 kWh
  4. 6 kWh Correct answer.

Explanation

Energy in kilowatt-hours equals power in kilowatts multiplied by time in hours. Two kilowatts times three hours gives 6 kWh.

Question 27Basic Electrical Principles and Calculations

Three resistors of 4 ohms each are connected in series. What is the total resistance?

  1. 64 ohms
  2. 12 ohms Correct answer.
  3. 1.33 ohms
  4. 4 ohms

Explanation

In a series circuit the total resistance is the sum of the individual resistances. Adding 4, 4 and 4 ohms gives 12 ohms.

Question 28Basic Electrical Principles and Calculations

A circuit has a 24 V supply and total resistance of 8 ohms. What current flows?

  1. 192 A
  2. 3 A Correct answer.
  3. 0.33 A
  4. 16 A

Explanation

Ohm's law gives current as voltage divided by resistance. Dividing 24 V by 8 ohms yields 3 A.

Question 29Basic Electrical Principles and Calculations

What is the frequency of a supply whose waveform completes 50 cycles in one second?

  1. 0.02 Hz
  2. 100 Hz
  3. 50 Hz Correct answer.
  4. 25 Hz

Explanation

Frequency is the number of complete cycles per second, measured in hertz. Fifty cycles in one second is therefore 50 Hz.

Question 30Basic Electrical Principles and Calculations

A sinusoidal supply has a peak voltage of 340 V. What is its approximate RMS voltage?

  1. 680 V
  2. 170 V
  3. 240 V Correct answer.
  4. 340 V

Explanation

For a sine wave the RMS value equals the peak value divided by the square root of two, about 0.707 times the peak. Multiplying 340 V by 0.707 gives approximately 240 V.

Question 31Basic Electrical Principles and Calculations

What is the effective resistance of two 10 ohm resistors connected in parallel?

  1. 2.5 ohms
  2. 10 ohms
  3. 20 ohms
  4. 5 ohms Correct answer.

Explanation

For equal resistors in parallel the equivalent resistance is one value divided by the number of branches. Ten ohms divided by two gives 5 ohms.

Question 32Basic Electrical Principles and Calculations

Which statement correctly describes the voltage across components connected in parallel?

  1. It is the same across each component Correct answer.
  2. It is zero across each component
  3. It equals the total current
  4. It divides in proportion to resistance

Explanation

Parallel branches are connected across the same two nodes, so each branch experiences the same potential difference. Current divides between the branches instead.

Question 33Basic Electrical Principles and Calculations

A conductor of resistance 20 ohms carries 3 A. What power is dissipated as heat?

  1. 180 W Correct answer.
  2. 6.67 W
  3. 60 W
  4. 23 W

Explanation

Power dissipated in a resistor can be found from current squared times resistance. Three squared is nine, and nine times 20 ohms gives 180 W.

Question 34Basic Electrical Principles and Calculations

What is the periodic time of a 50 Hz alternating supply?

  1. 0.02 s Correct answer.
  2. 0.5 s
  3. 50 s
  4. 2 s

Explanation

Periodic time is the reciprocal of frequency. One divided by 50 Hz gives 0.02 seconds, the duration of one complete cycle.

Question 35Basic Electrical Principles and Calculations

In a series circuit containing several resistors, which quantity is identical through every component?

  1. Voltage
  2. Power
  3. Current Correct answer.
  4. Resistance

Explanation

A series circuit provides only one path for charge, so the same current passes through every component. The applied voltage is shared among the components in proportion to their resistances.

Question 36Basic Electrical Principles and Calculations

A 100 W lamp and a 40 W lamp are both designed for 240 V. Which statement about their resistances is correct?

  1. Resistance cannot be compared from these ratings
  2. The 40 W lamp has the higher resistance Correct answer.
  3. The 100 W lamp has the higher resistance
  4. Both lamps have equal resistance

Explanation

At a fixed voltage, power equals voltage squared divided by resistance, so resistance is inversely proportional to power. The lower-power lamp must therefore have the higher resistance.

Question 37Basic Electrical Principles and Calculations

A 6 ohm resistor and a 3 ohm resistor are connected in series across a 9 V supply. What is the voltage across the 6 ohm resistor?

  1. 3 V
  2. 4.5 V
  3. 6 V Correct answer.
  4. 9 V

Explanation

The total resistance is 9 ohms, so the current is 9 V divided by 9 ohms, which is 1 A. The voltage across the 6 ohm resistor is then 1 A times 6 ohms, giving 6 V.

Question 38Basic Electrical Principles and Calculations

Two parallel branches of 12 ohms and 6 ohms are connected across a 12 V supply. What is the total current drawn from the supply?

  1. 2 A
  2. 1 A
  3. 3 A Correct answer.
  4. 4 A

Explanation

Each branch sees the full 12 V, so the 12 ohm branch draws 1 A and the 6 ohm branch draws 2 A. The supply current is the sum of the branch currents, giving 3 A.

Question 39Basic Electrical Principles and Calculations

A coil has an inductive reactance of 8 ohms and a resistance of 6 ohms in series. What is the impedance of the coil?

  1. 10 ohms Correct answer.
  2. 48 ohms
  3. 2 ohms
  4. 14 ohms

Explanation

Resistance and inductive reactance are 90 degrees out of phase, so they combine as the square root of the sum of squares. The square root of 36 plus 64 is the square root of 100, which is 10 ohms.

Question 40Basic Electrical Principles and Calculations

A 240 V heater draws 5 A. If the supply voltage falls to 120 V and resistance stays constant, what current does it draw?

  1. 5 A
  2. 2.5 A Correct answer.
  3. 1.25 A
  4. 10 A

Explanation

The resistance is 240 V divided by 5 A, which is 48 ohms. At 120 V the current is 120 V divided by 48 ohms, giving 2.5 A, so halving the voltage halves the current.

Question 41Electrical Materials, Tools and Hand Skills

Which hand tool is specifically designed to strip insulation from a conductor without nicking the copper?

  1. Long-nose pliers
  2. Side-cutting pliers
  3. Lineman's pliers
  4. Wire stripper Correct answer.

Explanation

A wire stripper has sized notches or an adjustable blade stop that scores and pulls off insulation to a set depth, so the blade cannot reach the copper. Pliers of any type grip, bend, or cut but do not control blade depth, so they commonly nick the conductor.

Question 42Electrical Materials, Tools and Hand Skills

What is the main purpose of a torque screwdriver when terminating conductors in a panel?

  1. To speed up tightening of large lugs
  2. To remove insulation from small conductors
  3. To tighten terminals to the manufacturer's specified value Correct answer.
  4. To measure circuit current during testing

Explanation

Terminals must be tightened to the torque value stated on the equipment label or in the instructions; too little torque leaves a loose, heat-producing joint and too much can damage the lug. A torque screwdriver slips or clicks at the set value so the joint matches the manufacturer's specification.

Question 43Electrical Materials, Tools and Hand Skills

A copper conductor is being pulled through a long conduit run. Which practice best protects the insulation during the pull?

  1. Using a pulling lubricant and a proper pulling grip Correct answer.
  2. Twisting all conductors tightly together before pulling
  3. Pulling with a powered winch at high speed
  4. Bending the conductor sharply around the conduit lip

Explanation

Lubricant reduces friction along the raceway and a correct pulling grip distributes tension so the insulation is not abraded or stretched at the connector. Sharp bends and excessive speed concentrate stress and can tear the jacket or deform the copper.

Question 44Electrical Materials, Tools and Hand Skills

Which type of screwdriver tip is intended for a Phillips-head screw?

  1. A square-recessed tip
  2. A flat, wedge-shaped blade
  3. A cross-shaped tapered tip Correct answer.
  4. A star-shaped six-point tip

Explanation

A Phillips driver has a cross-shaped tip that self-centers in the matching recess and is designed to cam out under excess torque. The flat blade, square recess, and six-point star shapes each match entirely different screw heads.

Question 45Electrical Materials, Tools and Hand Skills

When should a hard hat be replaced even if it shows no visible cracks?

  1. After the manufacturer's stated service life or a damaging impact Correct answer.
  2. Only when the suspension strap breaks
  3. Only after it has been dropped once
  4. Never, because hard hats are permanent equipment

Explanation

Hard hat shells are made of polymers that degrade from sunlight, heat, and chemicals, so manufacturers assign a service life after which the shell must be retired. A hard hat that has taken a significant impact must also be replaced because hidden stress damage can reduce protection.

Question 46Electrical Materials, Tools and Hand Skills

Which tool is used to cut a clean thread on the end of a rigid metal conduit?

  1. A pipe reamer
  2. A knockout punch
  3. A conduit bender
  4. A die head on a threader Correct answer.

Explanation

A die head carries cutting dies sized to the conduit trade size and cuts the external thread that mates with couplings and fittings. Reamers smooth the cut edge, benders form bends, and knockout punches make holes in enclosures, so none of them creates threads.

Question 47Electrical Materials, Tools and Hand Skills

Why is the inside edge of a freshly cut metal conduit reamed before conductors are installed?

  1. To remove burrs that could damage insulation Correct answer.
  2. To enlarge the conduit trade size
  3. To make the conduit easier to bend
  4. To prepare the surface for threading

Explanation

Cutting leaves a sharp internal burr that can scrape and cut conductor insulation as wire is pulled through. Reaming smooths that edge so the raceway does not damage the conductors it carries.

Question 48Electrical Materials, Tools and Hand Skills

A conductor must be joined to another inside a junction box. Which method produces a mechanically and electrically sound splice?

  1. Using a listed connector rated for the conductor size and material Correct answer.
  2. Clamping the ends under a single box screw
  3. Bending both ends into a hook and leaving them untwisted
  4. Twisting the bare ends together and taping them

Explanation

A listed splicing connector is tested for the conductor size, material, and current it will carry, so it gives a reliable mechanical and electrical joint. Bare twisting, untwisted hooks, or a single screw are not recognized methods and can loosen, overheat, or fail under load.

Question 49Electrical Materials, Tools and Hand Skills

Which unit expresses the cross-sectional area of a conductor in the inch-pound system?

  1. Volt-ampere
  2. Circular mil Correct answer.
  3. Ampere-hour
  4. Ohm per thousand feet

Explanation

A circular mil is the area of a circle one mil (one thousandth of an inch) in diameter, and conductor areas in North American practice are stated in circular mils or thousands of circular mils. The other units describe power, resistance, or charge, not area.

Question 50Electrical Materials, Tools and Hand Skills

Why are aluminum conductors often terminated with connectors marked AL and installed with an antioxidant compound?

  1. To make the conductor easier to bend
  2. To prevent oxidation that raises joint resistance Correct answer.
  3. To reduce the weight of the termination
  4. To increase the current rating of the conductor

Explanation

Aluminum forms a tough oxide film that increases contact resistance and can lead to overheating at terminations. A connector listed for aluminum plus an antioxidant compound breaks down and excludes that oxide, keeping the joint resistance low.