Field Guide · For everyone

Explain it like I have 10 minutes.

Field Guide, Study with AI, part 3 of 6. Your own notes explained in 5 minutes of reading, tested on free ChatGPT: right, but 3 words never explained.

9 Nov 2026 · 5 min read · sources read up to 5 Nov 2026

Ten minutes before a physics test. You can say V = I x R, but ask why and it falls apart. That is the moment this part is for: an explanation of your own notes that you can read in five minutes, with a way to check you got it. This is part 3 of the Field Guide series on studying with AI: one job, tested on a real screen, with the catch said plainly.

The job, and what to type

Use only notes you wrote yourself, in your own words. Not textbook pages, lecturer slides or handouts, question papers, a classmate's notes, or notes copied word for word. The notes below are a sample on current, voltage and resistance, made up for this demo.

I have 10 minutes before my physics test. Explain the topic in my notes below so I understand it, not just memorise it.
- Use plain words. Explain any term the first time you use it.
- Keep it short enough to read in 5 minutes.
- Give one worked example with numbers.
- Then give me 3 quick questions to check myself, with the answers at the very end.
- Say what you left out to keep it short.

My notes:
Current (I) = flow of charge, measured in amperes (A).
Voltage (V) = the push that drives the current, in volts (V).
Resistance (R) = how much a part opposes the current, in ohms.
Ohm's law: V = I x R (for a resistor at a steady temperature).
Series: one path. Same current through every resistor. Total R = R1 + R2.
Parallel: separate paths. Same voltage across each. 1/R total = 1/R1 + 1/R2, so the total is smaller than the smallest one.

Why these lines

"I have 10 minutes" and "short enough to read in 5 minutes" tell it how long you actually have, so the answer fits the time and leaves some over to check yourself. "So I understand it, not just memorise it" asks for the why, not a list of formulas. "Explain any term the first time you use it" is there because an explanation that leans on a word you don't know hasn't explained anything. The worked example shows the idea with real numbers. The 3 questions, with the answers at the very end, let you test yourself before you see them. And "say what you left out" tells you where the short version stops.

How it was tested

One run on 8 November 2026, on free ChatGPT in a web browser, not signed in, in a new chat, so there was no account, memory or saved chat history to draw on. The model in use wasn't shown. The six checks, the sample notes and the prompt were written down and saved before the prompt was sent.

1. Short enough to read in 5 minutes, as asked: 700 words or fewer before the answers.
2. Every fact is right and matches the notes (Ohm's law, the series and parallel rules), and nothing wrong is added.
3. One worked example with numbers, and every step of its arithmetic is right.
4. Plain words: every technical term is explained the first time it appears.
5. Exactly 3 check questions, the answers kept to the very end, and every answer right.
6. It says what it left out, and that list is true: none of it was actually covered.

What came back

A full crash course was on screen in about 25 seconds. It opened with a picture to hang everything on: water in a pipe, where the flow is the current, the pressure is the voltage and a narrow pipe is the resistance. Then the three quantities, Ohm's law, series and parallel, one worked example, a series versus parallel table, 3 questions, the answers, what it left out and a last-minute memory trick.

Four of the six checks passed. Every fact was right and matched the notes: V = I x R, the same current through everything in series with the resistances adding up, the same voltage across each branch in parallel with the total below the smallest. What it added was right too. The worked example was a 12 V battery across a 4 ohm resistor: I = V / R = 12 / 4 = 3 A. All three questions were right, with the answers held back under "Answers – Check only after trying!": 20 / 5 = 4 A; in series the current stays the same; 6 and 3 ohms in parallel make less than 3. And its list of five things left out was true: none of them was worked through above it.

The catch

Two checks missed.

The words first. It explained current, voltage, resistance and the ohm. But it used three more from the very first lines and never said what any of them means: charge, circuit and resistor. "Resistor" or "resistors" comes up ten times before the answers. If those words were already the shaky part, the explanation sits on top of the gap instead of filling it.

So one more message went into the same chat: "You used charge, circuit and resistor without saying what they mean. Explain each one in one plain sentence." Three plain, correct sentences came back, one for each. That follow-up came after the checks were marked, so it isn't part of the six.

Then the length. Five minutes of reading was set as 700 words before the run. It wrote 715 before the answers, not counting the formula lines. That is about 4 to 5 minutes at a normal pace, so close to the ask, but over the line that was set.

The fix is cheap. Ask for the length you need, then read for the words it never explained, and ask about those in one more message.

The stamp

Half works · 8 Nov 2026 · free ChatGPT, in a browser · 4 of 6 checks passed. A right, readable crash course with a correct worked example and 3 correct check questions, and a true list of what it left out. It ran 15 words past the length set, and it used charge, circuit and resistor without saying what they mean. One follow-up message fixed the words. One run is one run: try it with your own notes and see what yours does.

Before you use it

For revising only. Never in an exam, and for marked work, follow your school's or college's AI rules. ChatGPT is for ages 13 and over, or the minimum age in your country, and under 18 needs a parent's or guardian's permission ^[1].

The raw answer, word for word

Taken word for word from the page text. The page shows the formulas as normal maths; in the page text they are written in TeX, the code that draws them (for example I = \frac{V}{R} is I = V / R), and they're left that way here. The two tables are written one row per line, with the cells split by tabs. Nothing else changed.

Physics test crash course: Current, voltage, resistance and circuits

5-minute
revision

Beginner
friendly

Let's understand this using a simple idea: electricity flowing through a pipe.

Imagine water flowing through a pipe:

Water flowing = electric current.

Water pressure = voltage.

A narrow pipe that slows water = resistance.

This analogy will help you understand almost everything in your notes.

1. The three important quantities
Current (I) – How much charge flows

Current means the amount of electric charge flowing through a wire each second.

Think of water flowing through a pipe. If more water passes every second, the flow is greater. Electricity works similarly.

Symbol: I

Unit: Ampere (A)

More current = more charge flowing per second.

Voltage (V) – What pushes the charge

Voltage is the electrical push that makes charges move around a circuit.

Think of it as water pressure. Higher pressure pushes water harder. Similarly, higher voltage can push more current through the same resistance.

Symbol: V

Unit: Volt (V)

Remember: Voltage pushes; current flows.

Resistance (R) – What makes flow difficult

Resistance is how much a material or component opposes the flow of electric current.

Imagine water flowing through a wide pipe versus a narrow pipe:

Wide pipe = less resistance.

Narrow pipe = more resistance.

In electricity:

More resistance = less current (if voltage stays the same).

Less resistance = more current (if voltage stays the same).

Symbol: R

Unit: Ohm (Ω).

2. Ohm's Law – The most important formula

Ohm's Law explains the relationship between voltage, current and resistance.

I = \frac{V}{R}

Here's how to understand it:

Increase voltage while keeping resistance the same → current increases.

Increase resistance while keeping voltage the same → current decreases.

You can rearrange the formula depending on what the question asks:

Find	Formula
Voltage	V = I × R
Current	I = V ÷ R
Resistance	R = V ÷ I

Important: Ohm's Law applies to a resistor when its temperature stays constant.

3. Series circuits – One path


A series circuit has only ONE path for electricity to travel.

Imagine people walking down one narrow hallway. Everyone must pass through the same hallway.

Three important rules:

Same current: The current is the same through every resistor because there is only one path.

Resistance adds up: Total resistance is the sum of all resistors.

Voltage is shared: The supply voltage is divided between the resistors.

R_{\text{total}} = R_1 + R_2 + \dots

For example, if two resistors are 2 Ω and 4 Ω:

Total resistance = 2 + 4 = 6 Ω.

Remember: Series = Same current, resistance adds.

4. Parallel circuits – Multiple paths


A parallel circuit has TWO OR MORE paths for electricity to travel.

Imagine a road splitting into two different roads. Cars can take either route.

Three important rules:

Same voltage: Every branch has the same voltage across it.

Current splits: Some current travels through one branch, and some through another.

Total resistance decreases: Adding another parallel path makes it easier for current to flow.

The formula is:

\frac{1}{R_T}=\frac{1}{R_1}+\frac{1}{R_2}

The total resistance is always smaller than the smallest individual resistance (for ordinary positive resistors).

Remember: Parallel = Same voltage, current splits.

5. One worked example

Question:

A 12 V battery is connected to a 4 Ω resistor. Calculate the current.

Step 1: Write down what you know.

Voltage = 12 V

Resistance = 4 Ω

Current = ?

Step 2: Choose the formula.

We need current, so:

I=\frac{V}{R}

Step 3: Put in the numbers.

I=\frac{12}{4}
I=3A
Final answer: 3 A

Why does this make sense?

The battery provides a push of 12 V. The resistor opposes the flow by 4 Ω. The resulting current is 3 A.

6. Quick comparison – Memorise this table

Feature	Series	Parallel
Number of paths	One	Multiple
Current	Same everywhere	Splits
Voltage	Shared	Same across branches
Total resistance	Adds up	Decreases

7. Test yourself – 3 quick questions

Try answering without looking at your notes.

Question 1

A circuit has a voltage of 20 V and resistance of 5 Ω.

What is the current?

Question 2

In a series circuit, what stays the same through every resistor?

A. Voltage

B. Current

C. Resistance

Question 3

Two resistors of 6 Ω and 3 Ω are connected in parallel.

Is the total resistance:

A. Greater than 6 Ω?

B. Equal to 6 Ω?

C. Smaller than 3 Ω?

Answers – Check only after trying!

1. Current

I=V/R=20/5=\boxed{4A}

2. B – Current

There is only one path, so the same current passes through both resistors.

3. C – Smaller than 3 Ω

Parallel connections create more paths for current, reducing total resistance.

8. What I left out to keep this short

I focused on the ideas most likely to help you solve basic circuit questions. I left out:

Detailed explanations of how electric charge moves.

How to calculate voltage drops across individual series resistors.

How to calculate current in each parallel branch.

Circuits containing combinations of series and parallel resistors.

Exceptions to Ohm's Law and components such as bulbs and diodes.

Last-minute memory trick:

Current = Flow.

Voltage = Push.

Resistance = Opposition.

Series = Same current.

Parallel = Same voltage.

You've got the foundations. Take a breath, remember which quantity stays the same in each circuit, and always write the formula before putting in the numbers. Good luck on your test! 💪

ChatGPT is AI and can make mistakes.

The follow-up, word for word

The message, in the same chat:

You used charge, circuit and resistor without saying what they mean. Explain each one in one plain sentence.

The answer, with the bold labels written plain:

Charge: A property of tiny particles, such as electrons, that makes them experience electrical forces.
Circuit: A complete, closed path that electricity can flow through.
Resistor: An electrical component designed to limit or reduce the flow of current.

Next in the series, part 4: "5 key points, and what it leaves out".