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The ultimate guide for anyone who wishes to successfully pass an Electrical Comprehension test. Packed full of testing questions, this comprehensive guide will allow you to practice your electrical understandings, and enhance your overall performance.



What are Electrical Comprehension tests?

Electrical Comprehension tests are specifically designed to measure your performance in relation to electrical concepts. You need to engage with, and utilise, your skills and knowledge, and illustrate the key competencies and qualities required for particular job roles.

During an Electrical Comprehension test, you are likely to encounter the following types of questions:

Simple Circuits Electrical Symbols Switches Lamps
Electrical Safety Hazard Perception Electrical Energy Currents
Voltages Resistance Resistors Diodes
Electrical Measurements Process Flow Signal Flow Potential Difference
Electrical Schematics Ohm's Law Electrons Ammeter
Units of Electricity Particles Atoms Energy Transfers

What are Electrical Comprehension tests?

Anyone who is applying for a job that requires strong levels of electrical and technical ability will most likely be expected to undertake an Electrical Comprehension Test.


Jobs that often require candidate's to sit an Electrical Comprehension test are as follows:

  • Royal Air Force;
  • Armed Forces;
  • Technical Positions;
  • Electricians;
  • Signal Repairers;
  • Wireman;
  • Engineers;
  • Electrical Engineering;
  • Physics.

Please note, that the list above is not exhaustive. Other jobs may require you to sit an Electrical Comprehension test. Remember to find out as much information regarding the selection process for the job you have applied for. If you know that you have to sit some of psychometric assessment, this will enable you to prepare to the fullest.

How to prepare

The best way to prepare for an Electrical Comprehension assessment is to simply undergo as much practice as you possibly can. The more you practice, the better chance you have at successfully passing the assessment. Here at How2become, we have done our utmost to ensure you with a guide packed full of practice questions in order to better your knowledge and performance regarding electrical ability.

Top tips to improve your chances of success

The following is a list of key bullet points that we believe will assist you through the preparation period of conducting an Electrical Comprehension test. There are more top tips and advice in our guide which we highly recommend on reading to ensure you are fully equipped for the entire process.

Carry out lots of sample testing questions which focus on the subject you are preparing for. In regards to electrical tests, it is vitally important that you understand what the question is asking. You need to read the question carefully to ensure you have read it correctly.

Whilst undertaking sample tests, it is important that, if you get a question wrong, you spend time working out why you got it wrong. Within this guide, we have provided answers and detailed explanations to assist you through your learning process. If you get a question wrong, consider 'why' you have got it wrong. Read through the answers and explanations in order to improve your overall knowledge.

When practising, you must ensure that you work on your speed as well as your accuracy. Most tests are administered under time limits, and therefore you will be expected to answer as many questions as possible within the allotted time given. Having said this, you do not want to sacrifice the accuracy of your answers. Do not rush through the questions; you want to avoid making careless mistakes.

What does the guide include?

Within this guide, we have provided you with 100 basic sample questions, and 100 advanced questions, that allow you to better your overall performance.


For any Electrical Comprehension test, it is important that you have grasped the basics of electrical understandings. You need to be able to demonstrate good understandings in relation to electrical circuits, electrical elements, functionality and significance.

Within any basic electrical assessment, you most likely come across the following types of questions:


Jobs that often require candidate's to sit an Electrical Comprehension test are as follows:

  • Circuits;
  • Electrical Symbols;
  • Series and Parallel Circuits;
  • Alternating and Direct Currents;
  • Voltages;
  • Resistance;
  • Resistors;
  • Diodes.

Before moving on to the advanced section, you should brush up on your physics and electrical knowledge to ensure yourself with the best practice.


Depending on the type of job you are applying for, will depend on the complexity of the Electrical test. If you are applying for a high-tech position, it is more than likely that the questions you will be answering in your assessment will be of a complex nature.

Types of questions that you are likely to encounter are as follows:

  • Series and Parallel Circuits;
  • Transformers;
  • Monitoring and Measuring Alternating and Direct Currents;
  • Voltages;
  • Tolerable Resistances;
  • Impedances;
  • Magnetic Fields;
  • Wheatstone Bridge circuit;
  • Earth-Fault Loops;
  • Eddy Currents;
  • Potential Difference;
  • Capacitances;
  • Residual current device (RCM);
  • Resistors;
  • Diodes.

Please note, the above list is not exhaustive. Your assessment will contain questions that are relevant to the job you are applying for, therefore we have provided a general overview of the typical questions found on an Electrical assessment

Practice Electrical Comprehension tests

Below, we have provided you with example questions taken from our guide to highlight the types of questions you will face in not only our guide, but in an actual Electrical Comprehension assessment.

Example 1 – BASICS

What are the basic particles that make up an atom?


A – Protons, neutrons and particles.

B – Protons and electrons.

C – Neutrons, protons and electrons.

D – Mesons, neutrons and electrons.

How to work out the question

Step 1 = this question requires prior knowledge regarding atoms and particles.

Step 2 = that is why it is important to research and revise basic electrical concepts.


C – Neutrons, protons and electrons.

Example 2 – BASICS

In the following circuit, if switch A closes, and switch B remains open, what will happen?


A – Bulbs X, Y, and Z will illuminate.

B – Bulb X will illuminate only.

C – Bulbs Y and Z will illuminate.

D – No bulbs will illuminate.

How to work it out

Step 1 = you need to understand how electrical circuits, and what happens to the electrical circuit if something changes i.e. if a switch turns on or off.

Step 2 = if switch A closed, and switch B remains open, no bulbs would illuminate. Even with switch A being an 'on-switch', the fact that switch B remains open means that the power supply (i.e. the battery) cannot supply the power because the circuit is broken.


– D - no bulbs will illuminate

Example 3 – BASICS

In the following circuit, if bulb 3 is removed and the switch is closed, which bulbs will illuminate?


A –Bulb 4 will illuminate.

B – Bulbs 1, 2 and 4 will illuminate.

C – Bulbs 2 and 4 will illuminate.

D – Bulbs 1 and 2 will illuminate.

E – No bulbs will illuminate.

How to work it out

Step 1 = y if the switch is closed, and bulb 3 is removed from the circuit, that means only bulbs 1 and 2 will illuminate.

Step 2 = Bulb 4 will not illuminate because the removal of bulb 3 breaks the path of wiring and therefore prevents bulb 4 from lighting up.

Step 3 =the removal of bulb 3 is on a different path to bulbs and 1 and 2, and therefore does not affect them from illuminating.


D - bulbs 1 and 2 will illuminate

Example 1 – ADVANCED

What are the minimum and maximum acceptable values if a resistor has the resistance of 14 kΩ and can tolerate ±20%?

Minimum value =

Maximum value =

How to work it out

Step 1 = 14,000 ÷ 100 x 20 = 2,800.

Step 2 = Minimum = 14,000 – 2,800 = 11,200 Ω, or 11.2 kΩ

Step 3 = Maximum = 14,000 + 2,800 = 16,800 Ω or 16.8 kΩ


Minimum = 11.2 kΩ

Maximum = 16.8 kΩ

Example 2 – ADVANCED

John turns on his electrical heater. The electrical heater uses a supply of 310 voltages, and the current is 11 A. John wants to work out the resistance of his electrical heater. Calculate the resistance of the electrical heater. Rounded to two decimal places.

How to work it out

Step 1 = n order to work out the resistance, you would need to use the following equation: Resistance = voltage ÷ current = 310 ÷ 11 = 12.1818. To two decimal places = 12.18 ohms.


12.18 Ω

Example 3 – ADVANCED

Using the below Wheatstone bridge circuit, calculate the resistance of R3.


How to work it out

Step 1 = in order to work out the resistance, you should use the following equation:

R1 ÷ R2 = R3 ÷ R4

Step 2 = R1 and R2 = 180 ÷ 400 = 0.45. So, R3 ÷ R4 needs to be equivalent to 0.45

Step 3 = R3 = (180 x 600) ÷ 400 = 270

Step 4 = you can double check to make sure that you have the correct answer by doing the following:

180 ÷ 400 = 0.45.

270 ÷ 600 = 0.45.


R3 = 270 Ω

Electrical Comprehension guide

By the end of the guide, you will be able to:

  • Demonstrate a basic understanding in relation to technical and electrical concepts;
  • Understand the meaning of electrical signs and what they represent;
  • Understand the importance of electrical safety and the dangers involved;
  • Illustrate the important concepts in relation to electrical components including: currents, voltages, resistances, energy and circuits;
  • Improve your knowledge and understanding of electrical concepts;
  • Engage with the basics of electrical comprehension and advance your knowledge to show stronger levels of understanding.

Electrical Comprehension : Guide Contents


The Electrical Comprehension workbook contains:

  • TIPS top tips for passing the tests including what you should do and what you should try to avoid;
  • 200 TESTING QUESTIONS – the workbook purposely provides you with lots and lots of sample questions for you to get your head around, and to ensure you are ready to take your actual Electrical Comprehension test;
  • IDEAL – for anyone who wishes to successfully pass an Electrical assessment;
  • DETAILED EXPLANATIONS – this book contains all the answers and explanations of how to work out every single question, so you are able to correct your mistakes and know how to work the question out for future reference;
  • A COMPREHENSIVE GUIDE! – This guide is packed with all the information, advice and questions you will need to prepare for, and pass your Electrical Comprehension test.

Electrical Comprehension tests:

Sample Questions and Answers





Electrical Comprehension Tests Workbook

  • 100s of Electrical Comprehension Practice Questions
  • Detailed Answers to each Question
  • Beginner and Advanced Testing Sections
  • Learn how to pass all electircal comprehension tests
  • A full breakdown of circuits and electrical comprehension questions
  • Expert Assessment Advice
  • Buy now for only £12.97+ P&P