Learn by Novus · Open practice pack v1

Electrical reasoning: applied practice: open practice pack: learner worksheet

20 untimed questions across 4 authored sections.

This is untimed educational practice for one applied skill. It is not a clinical, diagnostic, employment, or professionally recognized assessment, it does not produce a score or credential, and for the judgement and safety families it is not a substitute for your employer's own policies, training, or legal duties.

Learner worksheet

Each item describes a circuit or an electrical situation in words. You need Ohm's law, the power relationship, and the difference between series and parallel connection. All of which the lesson works through. Nothing here is timed, and nothing here qualifies anyone to work on live equipment.

Choose one answer for each item. On a judgement item, more than one option is often defensible. Pick the one you would rate most effective, then check the worked explanation for why the runner-up is weaker.

Current, voltage, and resistance

Warm up on the three quantities every other item depends on, and on what each instrument actually measures.

1. electrical-reasoning-applied-s01-q01

A 12 V supply is connected across a single 4 ohm resistor. What current flows in the circuit?

  1. 0.33 A
  2. 3 A
  3. 48 A
  4. 8 A

Answer:

2. electrical-reasoning-applied-s01-q02

How is a voltmeter connected, and what does it read?

  1. In series with the component, reading the current through it
  2. In series with the component, reading the voltage across it
  3. In parallel across the component, reading the potential difference across it
  4. In parallel across the component, reading the current through it

Answer:

3. electrical-reasoning-applied-s01-q03

A heater on a 230 V supply draws 10 A. What power does it dissipate?

  1. 2300 W
  2. 23 W
  3. 240 W
  4. 2.3 W

Answer:

4. electrical-reasoning-applied-s01-q04

The resistance of a circuit is doubled while the supply voltage is held constant. What happens to the current?

  1. It doubles
  2. It is unchanged
  3. It quadruples
  4. It halves

Answer:

5. electrical-reasoning-applied-s01-q05

A cable is replaced by one of the same material and the same length but twice the cross-sectional area. What happens to its resistance?

  1. It doubles
  2. It is unchanged
  3. It halves
  4. It quadruples

Answer:

Series and parallel circuits

Combine resistances and predict what happens when one branch changes. Most circuit-reading mistakes come from applying a series rule to a parallel branch.

6. electrical-reasoning-applied-s02-q01

Three 6 ohm resistors are connected in series. What is the total resistance?

  1. 2 ohm
  2. 6 ohm
  3. 12 ohm
  4. 18 ohm

Answer:

7. electrical-reasoning-applied-s02-q02

Two 6 ohm resistors are connected in parallel. What is the total resistance?

  1. 3 ohm
  2. 6 ohm
  3. 12 ohm
  4. 1.5 ohm

Answer:

8. electrical-reasoning-applied-s02-q03

Several components are wired in series across a battery. Which statement describes the circuit correctly?

  1. The current divides between the components in proportion to their resistance
  2. The current is the same at every point, and the supply voltage divides across the components
  3. The current is greatest in the component nearest the battery
  4. The current is the same everywhere, and so is the voltage across each component

Answer:

9. electrical-reasoning-applied-s02-q04

In a string of decorative lamps, one lamp fails and every lamp in the string goes out. What does that tell you about the wiring?

  1. The lamps are in parallel
  2. The lamps are in parallel behind a shared switch
  3. The lamps are in series, so a break anywhere opens the only path
  4. The supply fuse is undersized

Answer:

10. electrical-reasoning-applied-s02-q05

Two identical lamps are connected in parallel across a 12 V supply. One lamp is unscrewed and removed. What happens to the other?

  1. It stays at the same brightness, because it still has the full 12 V across it
  2. It becomes noticeably brighter
  3. It goes out
  4. It dims to about half brightness

Answer:

Components and circuit reading

Identify what a component is for from what it does. These are the parts that appear on almost every schematic you will be asked to interpret.

11. electrical-reasoning-applied-s03-q01

Which component is designed to interrupt a circuit by melting when the current exceeds its rating?

  1. A capacitor
  2. A diode
  3. A fuse
  4. A transformer

Answer:

12. electrical-reasoning-applied-s03-q02

What does a diode do in a circuit?

  1. It stores charge and releases it later
  2. It allows current to flow in one direction only
  3. It steps an alternating voltage up or down
  4. It converts current into heat at a fixed rate

Answer:

13. electrical-reasoning-applied-s03-q03

A stairway light must be switchable from both the bottom and the top of the stairs. What arrangement does that?

  1. One single-pole single-throw switch at each end
  2. A relay at the light with a single switch
  3. A push-to-make button at each end
  4. A pair of two-way (single-pole double-throw) switches

Answer:

14. electrical-reasoning-applied-s03-q04

A transformer has a primary-to-secondary turns ratio of 20:1 and its primary is fed from 240 V AC. What is the secondary voltage?

  1. 12 V
  2. 480 V
  3. 4800 V
  4. 20 V

Answer:

15. electrical-reasoning-applied-s03-q05

A capacitor is connected across a steady DC supply through a resistor. What happens once it has fully charged?

  1. It passes direct current steadily from then on
  2. It behaves as a resistor of fixed value
  3. It reverses the polarity of the supply
  4. It blocks steady direct current, so the current in that branch falls to zero

Answer:

Fault-finding and electrical safety

Reason from a symptom to a likely cause, and from a hazard to the control that removes it. Follow your local wiring rules and competence requirements in real work.

16. electrical-reasoning-applied-s04-q01

A circuit breaker trips the instant one particular appliance is switched on, every single time. What does that pattern most suggest?

  1. A short circuit inside the appliance drawing a very large current immediately
  2. A slightly loose lamp in a different room
  3. Too many lights left on elsewhere in the building
  4. A capacitor that has discharged over time

Answer:

17. electrical-reasoning-applied-s04-q02

What condition is a residual current device (RCD) designed to detect?

  1. Sustained overload on the circuit
  2. A lightning surge on the incoming supply
  3. A supply voltage that has fallen below its nominal value
  4. A difference between the current in the line and neutral conductors, meaning current is leaking to earth

Answer:

18. electrical-reasoning-applied-s04-q03

What is the correct first step before working on a fixed electrical circuit?

  1. Put on insulating gloves and work carefully on the live circuit
  2. Switch the appliance off at its own switch
  3. Isolate at the supply, lock off the isolator, and prove the circuit dead with a tester that is itself proved before and after
  4. Turn off the nearest lighting switch

Answer:

19. electrical-reasoning-applied-s04-q04

A work lamp is noticeably dim when run from a long, thin extension reel, but normal when plugged into a nearby socket. What is the most likely cause?

  1. The lamp is rated for a higher wattage than the socket supplies
  2. Voltage drop along the long, thin cable
  3. The plug fuse is rated too high
  4. The extension reel uses a two-way switch

Answer:

20. electrical-reasoning-applied-s04-q05

A conductor inside a flexible lead is suspected of being broken. The lead is disconnected and tested end to end with a continuity tester. What reading indicates an intact conductor?

  1. A high resistance reading
  2. A reading close to zero ohms; a broken conductor reads as an open circuit
  3. A reading equal to the supply voltage
  4. No reading at all until the supply is restored

Answer: