A customer calls the new 7 kW wall unit on their drive "the charger". Which of these is one of the jobs that unit actually does on AC?

On AC the charge point confirms the connection, switches the supply, sets the current limit and protects. The tempting answer is the AC-to-DC conversion, but on AC that happens in the car’s on-board charger; only a DC station converts. A wall unit does not store energy or raise the voltage.

It tells the car the most current it is allowed to draw

It turns the AC supply into DC before it reaches the car

It stores energy so the car can charge faster at peak times

It raises the supply voltage so the battery fills more quickly

A charge point’s data plate says 7.4 kW and the car’s brochure says 60 kWh. Which statement about those two figures is right?

Kilowatts measure power, the rate energy flows, and that is what the circuit is designed for. Kilowatt-hours measure energy, which is how a battery is sized. Reading kWh as "power over an hour" sounds close but mixes the two up: a bigger battery takes longer at the same power, it does not change the current.

Both are power ratings; kWh is simply measured over an hour

kW is the rate energy flows; kWh is an amount of energy

kW is the energy the battery holds; kWh is the charge rate

Both are energy figures; kW is measured over one minute

A balanced three-phase charge point draws 32 A in each line on a 400 V supply. A colleague works out its power as 400 × 32 and gets 12.8 kW. Roughly what is the real figure?

For a balanced three-phase load P = √3 × V × I, so 1.732 × 400 × 32 is about 22 kW, the same as 3 × 230 V × 32 A. The colleague’s 12.8 kW leaves out √3. 38 kW comes from multiplying the line voltage by three, and 7.4 kW is a single phase at 32 A.

Free mock exam

EV charging and the installer — EV Charging Installation Practice

Free topic-focused mock exam: all 30 questions on EV charging and the installer, drawn from the wider EV Charging Installation bank. 35-minute timer, 70% to pass, worked explanation on every question. Use this when you've taken the full mock once and want to drill the topics you got wrong.

Questions: 30
Time limit: 35 min
Pass mark: 70% · 21/30
Question bank: 30

Free, no sign-up. Retake as many times as you like — the questions are reshuffled, with the answer order changed.

Sample questions

01A customer calls the new 7 kW wall unit on their drive "the charger". Which of these is one of the jobs that unit actually does on AC?
- AIt turns the AC supply into DC before it reaches the car
- BIt stores energy so the car can charge faster at peak times
- CIt raises the supply voltage so the battery fills more quickly
- DIt tells the car the most current it is allowed to draw
Why: On AC the charge point confirms the connection, switches the supply, sets the current limit and protects. The tempting answer is the AC-to-DC conversion, but on AC that happens in the car’s on-board charger; only a DC station converts. A wall unit does not store energy or raise the voltage.
02A charge point’s data plate says 7.4 kW and the car’s brochure says 60 kWh. Which statement about those two figures is right?
- AkW is the energy the battery holds; kWh is the charge rate
- BBoth are power ratings; kWh is simply measured over an hour
- CBoth are energy figures; kW is measured over one minute
- DkW is the rate energy flows; kWh is an amount of energy
Why: Kilowatts measure power, the rate energy flows, and that is what the circuit is designed for. Kilowatt-hours measure energy, which is how a battery is sized. Reading kWh as "power over an hour" sounds close but mixes the two up: a bigger battery takes longer at the same power, it does not change the current.
03A balanced three-phase charge point draws 32 A in each line on a 400 V supply. A colleague works out its power as 400 × 32 and gets 12.8 kW. Roughly what is the real figure?
- A22 kW
- B38 kW
- C12.8 kW
- D7.4 kW
Why: For a balanced three-phase load P = √3 × V × I, so 1.732 × 400 × 32 is about 22 kW, the same as 3 × 230 V × 32 A. The colleague’s 12.8 kW leaves out √3. 38 kW comes from multiplying the line voltage by three, and 7.4 kW is a single phase at 32 A.

Common questions

Is the EV charging and the installer mock exam free?

Yes — 100% free, no sign-up needed. Questions are pulled at random from a substantial bank, with a worked explanation on every question after you submit.

Can I retake the mock exam?

Yes. Every attempt picks a different random selection and reshuffles the options, so each retake gives you genuinely new questions. No limit on retakes.

Does this count towards the real qualification?

No — this is independent practice material. To gain the actual qualification you need to sit the official assessment through an approved provider.