What topics are covered in Year 1 of an electrical apprenticeship?

Year 1 of a Level 3 Electrical Installation apprenticeship covers fundamental electrical theory including electrical units (volts, amps, ohms, watts), Ohm's Law, Kirchhoff's Laws, series and parallel circuits, DC and AC fundamentals, basic tools and their safe use, health and safety legislation (Health and Safety at Work etc. Act 1974, Electricity at Work Regulations 1989), PAT testing introduction, and basic wiring principles. You will also begin working towards your Level 3 Award in the Requirements for Electrical Installations (BS 7671:2018+A4:2026).

How do I revise Ohm's Law effectively?

Use the Ohm's Law triangle (V at the top, I and R at the bottom). Cover the unknown and the remaining symbols show you the formula: cover V → V = I × R; cover I → I = V / R; cover R → R = V / I. Practise transposing the formula with worked examples until it becomes automatic. The Elec-Mate flashcard system lets you drill Ohm's Law calculations with randomly generated values so you practise the maths, not just the formula.

What is the difference between series and parallel circuits?

In a series circuit, components are connected end-to-end so the same current flows through every component. The total resistance is the sum of all individual resistances (Rt = R1 + R2 + R3). Voltage is shared between components in proportion to their resistance. In a parallel circuit, each component has its own separate path connected between the same two points. The voltage across each branch is identical, but current divides between branches. Total resistance in a parallel circuit is always less than the smallest individual resistance.

What is the UK mains supply voltage and frequency?

The UK nominal supply voltage is 230 V AC at 50 Hz (hertz). The voltage tolerance is +10% / −6%, meaning acceptable voltages range from approximately 216.2 V to 253.0 V. The frequency tolerance is ±1%, so 49.5 Hz to 50.5 Hz. These limits sit with the Electricity Safety, Quality and Continuity Regulations (ESQCR), which require the distributor to declare the voltage and frequency of the supply and the extent of the permitted variations. You must know both values — they appear frequently in theory exams and practical assessments throughout your apprenticeship.

What health and safety legislation must I know in Year 1?

The key legislation for Year 1 includes: Health and Safety at Work etc. Act 1974 (HSWA) — the primary legislation placing duties on employers and employees; Electricity at Work Regulations 1989 — specific to electrical systems, and the reason safe isolation is not optional; Manual Handling Operations Regulations 1992 — risk assessment for lifting and moving loads; Personal Protective Equipment at Work Regulations 1992 — employer duty to provide PPE; and Control of Substances Hazardous to Health Regulations 2002 (COSHH). In construction, you will also encounter the Construction (Design and Management) Regulations 2015 (CDM).

What tools should a first-year apprentice know?

First-year apprentices should be able to identify, name, and use correctly: screwdrivers (flathead, Pozidriv, insulated), wire strippers, cable cutters, pliers (combination, long-nose), hammer, chisel, cold chisel, spirit level, tape measure, bradawl, cordless drill, and voltage indicator. You must also understand when and how to use PPE including insulated gloves, safety glasses, hard hat, steel-toecap boots, and hi-vis vest. Never use a tool you have not been trained on — always ask your supervisor.

What is PAT testing and do apprentices do it?

PAT stands for Portable Appliance Testing — the process of inspecting and testing in-service electrical equipment to check it is safe to use. Apprentices are introduced to it in Year 1 because it demonstrates fundamental principles: visual inspection, earth continuity testing, insulation resistance testing, and record keeping. Formal certification (City & Guilds 2377) is usually completed later in the apprenticeship or after qualification, but understanding the principles from Year 1 builds the inspection and testing skills that are central to the AM2 assessment and EICR work.

APPRENTICE STUDY GUIDE

Electrical Apprentice Year 1 Revision: First Year Study Guide

Everything you need to revise for Year 1 of your electrical apprenticeship — electrical units, Ohm's Law, series and parallel circuits, DC and AC fundamentals, basic tools, health and safety legislation, and an introduction to PAT testing.

Start 7-day free trial

Free for 7 days · No charge until day 8 · Cancel anytime · Used by 1,000+ UK electricians

12 min readUpdated 2026-08-07Andrew Moore, Founder of Elec-Mate

Written and reviewed by Andrew Moore, founder of Elec-Mate, against BS 7671:2018+A4:2026, IET Guidance Note 3 and the IET On-Site Guide.

ShareX in W

The short answer

What do you study in Year 1 of an electrical apprenticeship?

Year 1 covers the electrical units (volt, ampere, ohm, watt), Ohm's Law and how to transpose it, series and parallel circuits, DC and AC fundamentals at 230 V / 50 Hz, safe use of hand tools, health and safety law, and an introduction to inspection, testing and PAT.

Every regulation on this page is referenced against BS 7671:2018+A4:2026, the current edition of the Wiring Regulations.

Practise with a free mock exam

All free, no sign-up, 30 questions each with a worked explanation on every answer. Retake as many times as you like.

Qualification exams

Level 3 units

Level 2 units

Site safety cards

1,000+

UK electricians

“Replaced three separate apps with Elec-Mate. Certs, quotes, and scheduling all in one place.”
Daniel Palmer, DP Electrical · 5 out of 5

Key takeaways

01Ohm's Law (V = IR) is the single most important formula in Year 1 — know it forwards, backwards, and be able to transpose it for any unknown.
02The six core electrical units you must memorise: volt (V), ampere (A), ohm (Ω), watt (W), coulomb (C), and farad (F).
03Series circuits share the same current throughout; parallel circuits share the same voltage across each branch.
04AC (alternating current) in the UK runs at 230 V / 50 Hz — frequency and voltage values appear in every exam.
05Health and safety legislation you must know in Year 1: Health and Safety at Work etc. Act 1974, Electricity at Work Regulations 1989, and Manual Handling Operations Regulations 1992.
06Two rules from BS 7671:2018+A4:2026 you meet from day one: Reg 411.3.4 requires 30 mA RCD protection on AC final circuits supplying luminaires in domestic premises; Reg 421.1.7 requires AFDDs on socket-outlet circuits up to 32 A in high rise residential buildings, HMOs, purpose-built student accommodation and care homes, and recommends them elsewhere.

01 · Apprentice Study Guide

Year 1 Numbers to Memorise

These are the figures that come up again and again in Year 1 written papers and on site. Learn this table first — everything else on the page explains where the numbers come from.

Quantity	Value	Where it comes from
UK nominal supply voltage	230 V AC (line to neutral)	ESQCR declared voltage
UK supply frequency	50 Hz	ESQCR declared frequency
Voltage tolerance	+10% / −6% (216.2 V to 253.0 V)	ESQCR permitted variation
Frequency tolerance	±1% (49.5 Hz to 50.5 Hz)	ESQCR permitted variation
Period of one cycle at 50 Hz	T = 1 ÷ 50 = 0.02 s (20 ms)	T = 1 ÷ f
Peak voltage of a 230 V RMS supply	230 × √2 ≈ 325 V	Vpeak = Vrms × √2
Three-phase supply	400 V line to line / 230 V line to neutral, 120° apart	Standard UK LV distribution
RCD for domestic luminaire circuits	Rated residual operating current not exceeding 30 mA	BS 7671 Reg 411.3.4

Free download

Get the BS 7671 A4:2026 Cheat Sheet — free

Every key change in the 2026 amendment on one page. AFDDs, TN-C-S protection, new schedule columns, model forms. Pinned on your van dash.

Every regulation change summarised
New model forms (EIC + MEIWC)
Free PDF — no subscription

02 · Apprentice Study Guide

Electrical Units You Must Know

Before you can understand any electrical circuit, you need to know the units used to measure electrical quantities. These are the foundation of everything else in Year 1 and beyond. The International System of Units (SI) is used throughout electrical engineering.

Unit	Symbol	Quantity measured	What it means
Volt	V	Electromotive force (EMF) or potential difference (PD)	The electrical pressure that drives current around a circuit. Named after Alessandro Volta.
Ampere	A (I in formulas)	Electric current	The rate of flow of electric charge. One ampere is one coulomb passing a point per second. Named after André-Marie Ampère.
Ohm	Ω (R in formulas)	Resistance	Opposition to the flow of current. One ohm allows one ampere to flow when one volt is applied. Named after Georg Simon Ohm.
Watt	W (P in formulas)	Power	The rate at which energy is transferred or converted. P = V × I. Named after James Watt.
Coulomb	C (Q in formulas)	Electric charge	The charge transported by one ampere in one second. Q = I × t.
Farad	F	Capacitance	The ability to store electrical charge. One farad is very large, so capacitors are rated in microfarads (μF) or picofarads (pF). Named after Michael Faraday.

SI prefixes you will use every day

Electrical values are rarely a convenient size, so prefixes scale them up or down. Get these wrong in an exam and the answer is out by a factor of a thousand.

Prefix	Symbol	Multiplier	Example
mega	M	× 1,000,000	1 MΩ = 1,000,000 Ω
kilo	k	× 1,000	2.5 kΩ = 2,500 Ω
milli	m	× 0.001	100 mA = 0.1 A
micro	μ	× 0.000001	470 μF = 0.00047 F

03 · Apprentice Study Guide

Ohm's Law

Ohm’s Law is the single most important relationship in electrical theory. Published by Georg Simon Ohm in 1827, it defines the relationship between voltage, current, and resistance in a conductor at constant temperature.

To find	Formula	Worked example
Voltage (volts)	V = I × R	2 A through 6 Ω → V = 2 × 6 = 12 V
Current (amperes)	I = V ÷ R	12 V across 6 Ω → I = 12 ÷ 6 = 2 A
Resistance (ohms)	R = V ÷ I	12 V drawing 2 A → R = 12 ÷ 2 = 6 Ω

The Ohm’s Law triangle is the memory aid: draw a triangle with V at the top, I bottom-left, R bottom-right. Cover the unknown quantity and the two visible symbols show you the calculation. Practise transposing it until you no longer need the triangle — use the Elec-Mate Study Centre flashcards to drill it with randomly generated values.

04 · Apprentice Study Guide

Basic Circuit Theory

Every electrical circuit has the same basic parts: a source of EMF (battery or supply), conductors to carry current, a load that uses the energy, and a return path. Kirchhoff’s Laws describe how voltage and current behave once those parts are connected.

Kirchhoff’s Current Law (KCL): The total current entering a junction equals the total current leaving it. No current is lost at a junction — it is a statement of the conservation of charge.
Kirchhoff’s Voltage Law (KVL): The sum of all voltages around a closed loop equals zero. In practice: the supply voltage equals the sum of all the voltage drops across the resistances in the loop.

Series against parallel

This comparison is worth more marks than any other single topic in Year 1. Learn it as a set of contrasts rather than two separate lists.

Property	Series circuit	Parallel circuit
Current	The same through every component	Divides between the branches
Voltage	Divides in proportion to resistance	The same across every branch
Total resistance	Rt = R1 + R2 + R3	1/Rt = 1/R1 + 1/R2 + 1/R3
Compared with the individual resistors	Rt is greater than the largest resistor	Rt is always less than the smallest resistor
If one component goes open circuit	The whole circuit stops	The remaining branches keep working

05 · Apprentice Study Guide

DC Circuits

Direct current (DC) flows in one direction only. Batteries, solar panels, and USB chargers all produce DC. Understanding DC circuits is the foundation before moving on to AC, which is more complex because of the effects of inductance and capacitance.

Combining resistors

Resistors in series: Rt = R1 + R2 + R3. Example: 10 Ω + 15 Ω + 25 Ω = 50 Ω.
Two resistors in parallel: Rt = (R1 × R2) ÷ (R1 + R2). Example: 6 Ω and 12 Ω in parallel = (6 × 12) ÷ (6 + 12) = 72 ÷ 18 = 4 Ω.

Power and energy formulas

All three power formulas are equivalent — pick whichever suits the two values the question has given you.

Formula	Gives you	Use when you know
P = V × I	Power in watts	Voltage and current
P = I² × R	Power in watts	Current and resistance
P = V² ÷ R	Power in watts	Voltage and resistance
W = P × t	Energy in joules	Power in watts and time in seconds
kWh = kW × hours	Energy as billed	Load in kilowatts and running hours

06 · Apprentice Study Guide

AC Fundamentals

Alternating current (AC) repeatedly reverses direction. The UK mains supply is 230 V at 50 Hz — this is what you work with in almost every domestic and commercial installation. AC introduces frequency, period, peak values, and RMS values.

Frequency (f): The number of complete cycles per second, measured in hertz (Hz). UK mains: 50 Hz. USA mains: 60 Hz.
Period (T): The time for one complete cycle. T = 1 ÷ f. At 50 Hz: T = 1 ÷ 50 = 0.02 seconds (20 milliseconds).
Peak value: The maximum voltage reached during a cycle. For a 230 V RMS supply, Vpeak = 230 × √2 ≈ 325 V. This is why cable insulation is rated well above the nominal supply voltage.
RMS (root mean square): The effective value of AC — the value that produces the same heating effect as an equivalent DC voltage. The 230 V quoted for a socket-outlet is the RMS value. Vrms = Vpeak ÷ √2.
Three-phase supply: Commercial and industrial premises are supplied at 400 V line to line and 230 V line to neutral, with the three phases 120° apart. You will study three-phase in depth in Years 2 and 3.

Two BS 7671 rules you will meet on your first jobs

The current edition is BS 7671:2018+A4:2026. Two of its requirements shape almost every domestic board you will see as an apprentice.

Reg 411.3.4 — 30 mA RCD on domestic luminaire circuits: Within domestic (household) premises, additional protection by an RCD with a rated residual operating current not exceeding 30 mA shall be provided for AC final circuits supplying luminaires. This is a “shall” requirement, not guidance. It has been in BS 7671 since the 18th Edition was published in 2018.
Reg 421.1.7 — arc fault detection devices (AFDDs): Redrafted at Amendment 4. AFDDs conforming to BS EN 62606 shall be provided for single-phase AC final circuits supplying socket-outlets rated up to 32 A in high rise residential buildings (HRRBs), houses in multiple occupation, purpose-built student accommodation, and care homes. For all other premises, AFDDs are recommended on the same circuits. Where used, an AFDD is placed at the origin of the circuit it protects. Do not describe AFDDs as simply “recommended” in an exam answer — say where each wording applies.

In the app

Practise with unlimited mock exams

AI-generated mocks, instant marking, and explanations on every question — targeted at your weakest topics. From £6.99/mo.

Start practising free

07 · Apprentice Study Guide

Basic Electrical Tools

Selecting, using, and maintaining tools safely is assessed in the practical elements of your apprenticeship from day one. Your employer and your college will both expect you to handle tools confidently and safely.

Screwdrivers: Flathead for slotted screws, Pozidriv (PZ2 is the most common) for cross-head screws. Insulated screwdrivers are rated to 1000 V and are used wherever there is a risk of contact with live parts. Never use a damaged or wrongly sized screwdriver — it slips, and that causes injury and damage.
Wire strippers: Used to remove insulation without nicking the conductor. Set them to the correct conductor size — a nicked core is a reduced cross-sectional area and a hot joint waiting to happen.
Pliers: Combination pliers for gripping and cutting, long-nose for confined spaces and shaping conductors. Use insulated-handle pliers wherever live parts could be present.
Voltage indicator: A two-pole voltage indicator is what you use to prove a circuit is dead. HSE Guidance Note GS38 covers the selection and safe use of test equipment, leads and probes, and BS 7671 and GN3 both direct you to it. A non-contact tester alone is never sufficient confirmation that a circuit is dead.
Drill and bits: Cordless drills are standard; SDS for masonry. Always check for concealed cables and pipes with a cable and pipe detector before you drill, and wear eye protection.

08 · Apprentice Study Guide

Health and Safety Fundamentals

Health and safety is not a box-ticking exercise — it is a legal duty and a professional responsibility. Electrical work can be fatal if procedures are not followed. The legislation below is examinable in Year 1 and applies to your work every day.

Legislation	What it means for you
Health and Safety at Work etc. Act 1974 (HSWA)	The primary UK health and safety legislation. Employers must provide a safe working environment, safe equipment, and adequate training. Employees must take reasonable care for their own safety and that of others, and co-operate with their employer on health and safety matters.
Electricity at Work Regulations 1989 (EAWR)	Specific to electrical systems. Regulation 14 (Work on or near live conductors) is the one you will be asked about: work on or near a live conductor is only permitted where it is unreasonable for it to be dead, it is reasonable to work on or near it live, and suitable precautions are taken. Regulation 16 requires persons to be competent to prevent danger and injury. HSE publication HSR25 is the guidance on these Regulations.
Manual Handling Operations Regulations 1992	Employers must avoid manual handling where they reasonably can and, where they cannot, assess and reduce the risk. Electricians regularly move cable drums, consumer units and conduit that cause musculoskeletal injury if handled badly.
PPE at Work Regulations 1992	Employers must provide suitable PPE free of charge; employees must use it correctly and report defects. Typical electrical PPE: safety footwear, hi-vis, hard hat on construction sites, safety glasses, insulated gloves, and hearing protection with power tools.
Construction (Design and Management) Regulations 2015 (CDM)	Applies on construction sites. Among other duties, it is why a means of safe isolation must be designed in for future maintenance — the On-Site Guide treats failing to provide one as a potential CDM breach.

Safe isolation: the sequence

Safe isolation is the most important procedure you will learn all year. The sequence is: identify the circuit; switch off; lock off and retain the key; attach a warning notice; then test for dead with a proved voltage indicator. Prove the indicator on a known live source or a proving unit both before and after you test — that is the prove–test–prove method.

Guidance Note 3 requires an installation to be made dead and safely isolated wherever a test does not need it live, and refers you to HSE Guidance Note GS38 for the test equipment itself. The IET On-Site Guide sets out the practical steps and proof-of-dead procedure in Appendix M, Safe working practices. A non-contact tester is never your primary confirmation — always use a two-pole voltage indicator.

09 · Apprentice Study Guide

Introduction to PAT Testing

Portable Appliance Testing (PAT) is the inspection and testing of in-service electrical equipment to confirm it is safe to use. Apprentices are not usually expected to carry it out independently in Year 1, but the principles are on the syllabus and they introduce the inspection and testing habits that become central to your work later on.

1. Visual inspection: Always the first step. Check for damaged cables, cracked plugs, signs of overheating, the wrong fuse rating, and evidence of misuse. Most faults are found here, before any instrument comes out of the bag.
2. Earth continuity test: Confirms the protective conductor in a Class I appliance is connected and has a low resistance — typically taken as 0.1 Ω plus the resistance of the supply lead. Carried out with a PAT tester or a low-resistance ohmmeter.
3. Insulation resistance test: Applies 500 V DC between the live conductors and earth. For Class I appliances the reading should be at least 1 MΩ. It confirms the insulation has not broken down.
4. Record keeping: Every test is recorded: appliance description, asset number, results, pass or fail, date, and the name of the person testing. The records are the audit trail that shows a system of inspection and testing is actually in place.

These acceptance values are not set by BS 7671 — Part 6 of BS 7671 covers the verification of installations, not in-service equipment. In-service inspection and testing is covered by the IET Code of Practice for In-Service Inspection and Testing of Electrical Equipment, which is also the syllabus behind the City & Guilds 2377 award. Most apprentices take 2377 later in their training or shortly after qualifying.

10 · Apprentice Study Guide

Elec-Mate Study Tools for Year 1 Apprentices

Elec-Mate is built by electricians, for electricians and apprentices. The Study Centre holds the tools designed to get you through Year 1 theory and build the practical knowledge you need for your end-point assessment.

Flashcard revision system: Drill Ohm’s Law, electrical units, circuit theory, and health and safety legislation. Spaced repetition brings each card back at the point you are about to forget it, which is where the revision actually sticks.
AI tutor: Ask any Year 1 theory question and get a step-by-step explanation — worked calculations, and plain-English answers on the topics that take longest to click, like AC waveforms and circuit analysis.
Mock exams and course modules: Module-by-module content and timed mock papers, so you find the gaps before the exam does.

In the app

Start revising for Year 1 with Elec-Mate

Flashcards, AI tutor, mock exams, and course modules for electrical apprentices. Built for mobile — revise on your commute, on your break, or at home.

Try it free for 7 days

Frequently Asked Questions About Year 1 Electrical Apprenticeship

What electricians say

Verified reviews from the UK App Store.

One App for Everything!

Elec-Mate is my go to app for business and electrical work. It's feature rich without feeling cluttered. A true all in one app for quotes, certs, calculations, RAMS, EICRs, and more. I use it every day without fail, and it makes my workflow much smoother since I'm not jumping between apps anymore. The price-to-feature ratio is excellent. Any issues I've had, the developer responds within the hour and usually fixes them the same day. 100% recommend.

Fantastic app for electricians

I've used the app and the web based version for a while now and it's well worth the investment. If you're an apprentice or experienced Spark give it a go, you won't be disappointed.

Absolutely amazing

I've been using Elec-Mate for a while now, and honestly, it's one of the best apps I've ever downloaded. Every aspect of it feels thoughtfully designed, from the clean and intuitive interface to the powerful features that make everything so easy to manage. It's clear that a lot of care and attention went into building this app, and it shows in every detail.

Trusted by electricians across the UK

Real feedback from real sparks

“Replaced three separate apps with Elec-Mate. Certs, quotes, and scheduling all in one place.”

Daniel Palmer

Sole Trader · DP Electrical

“I've won two contracts this month because I could turn quotes around same-day with the AI cost engineer.”

Nathan Perry

Electrician · NP Electrical Services

“The study centre got me through my AM2. Mock exams and flashcards are brilliant.”

Jake Pizey

3rd Year Apprentice · Apprentice

7-day free trial

Revise Smarter with Elec-Mate

Flashcards, AI tutor, mock exams, and module-by-module course content built for electrical apprentices. Study on your phone, pass your exams. 7-day free trial.

Start your free trial

From £6.99/mo after the trial — no charge until day 8.