P3 General Studies: Home Electricity Safety (Paper 4 (error Clinic))

P3 General Studies: Home Electricity Safety (Paper 4 (error clinic))

2026-11-13

Tutor Prep Guide · conductors and insulators, power and electricity cost, series and parallel circuits, fuses and earth protection, and safe habits at home

P3 General Studies: Home Electricity Safety (Paper 4 (error clinic))

Paper four targets past errors: treating wet hands and wet floors as minor, wiping sockets with a wet cloth, forgetting the socket rating, adding parallel currents wrongly, and mixing up power and cost units.

Direct answers　For every item ask first whether water or dust has made a conducting path, then work out power and cost, and finally check whether the unit is watts, units or dollars.

01　Paper details (check answers afterwards)

Item	Detail
Questions	10
Suggested time	20
Difficulty mix	Foundation 3 · Intermediate 3 · Challenge 3 · Error redo 1
Chapter	Chapter: P3 General Studies: Home Electricity Safety
Level	parts of a closed circuit, conductors against insulators, series against parallel, adding up battery voltage, and electrical safety

02　Questions (10 items)

FoundationWhy are appliance cases and plugs made of plastic?
FoundationWhen unplugging, should you pull the cord or hold the plug body?
FoundationWhat danger comes from dusty plugs and sockets that have become damp?
IntermediateAn appliance runs at 220 V with a current of 0.2 A. What is its power?
IntermediateTwo appliances in parallel draw 0.5 A and 1.5 A. What is the total current?
IntermediateFive 60 W lamps are on together for 3 hours. What is the total energy used?
ChallengeA 13 A socket at 220 V is rated at 2860 W. How many watts over the limit is a 3000 W load?
ChallengeA 1000 W appliance runs for 15 minutes. How many units does it use?
ChallengeFrom the last question, what does that 15 minutes cost at $1.2 per unit?
Error redoA classmate wipes the sockets and switches with a wet cloth. What is wrong?

03　Answers and one-line notes

#	Answer	One-line note
1	To insulate, so that a user cannot touch a live part.	Plastic does not conduct, so it keeps the hand away from the metal.
2	Hold the plug body, because pulling the cord breaks the copper inside.	Pulling the cord loosens the joint over time and bare copper can be exposed.
3	Dust and water form a conducting path, so there may be leakage or a fire.	Damp dust destroys the insulation.
4	44.0 W	Two hundred twenty times zero point two equals 44.0 W.
5	2.0 A	Branch currents add in parallel: zero point five plus one point five gives 2.0 A.
6	0.9 units	The total power is 300 W, and three hundred times three gives 900 Wh, which is 0.9 units.
7	140 W	Three thousand minus two thousand eight hundred sixty gives 140 W.
8	0.25 units	Fifteen minutes is zero point two five hours, and one thousand times that gives 250 Wh, which is 0.25 units.
9	$0.3	Zero point two five times one point two equals 0.3.
10	The wet cloth carries water into the socket, and water with dust destroys insulation, so a shock is possible.	The power should be switched off first and a dry cloth used.

04　What to do after marking

After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
Repeat the same item two days later; move to the next paper only when both attempts are correct.
Parents only need the answer and note columns; there is no need to explain every item.

With all four done, go back to the chapter page and revise the three parts of a closed circuit plus three safety habits.Tutor Registration →

Questions and answers are written originally by the TutorZone team and are not taken from any school, publisher or examination authority paper. Every value is checked by computer.