How to Ace IGCSE Physics Paper 2: Multiple Choice (Extended)

Picking the right answer is a bit like grocery shopping

Stay with me here. You walk into a supermarket looking for olive oil. There are four bottles on the shelf. One is sunflower oil, one is rapeseed, one is olive oil but out of date, and one is the fresh olive oil you need. You don't taste all four. You read the labels, rule out the obvious mismatches, and grab the right one. That's essentially what IGCSE Physics Paper 2 asks you to do, forty times in forty-five minutes: read the label carefully, eliminate the wrong options, and pick the one that fits.

But Paper 2 isn't just any multiple choice paper. It's the Extended tier, which means it covers everything on the Core syllabus plus the additional content that only Extended candidates face. If you've been entered for Paper 2 instead of Paper 1, your teacher has decided you're capable of tackling the harder material. That's a compliment, but it also means you'll meet questions that go deeper, require more calculation steps, and test concepts that simply don't appear on the Core paper.

So how do you prepare for it properly? How do you avoid the traps Cambridge likes to set? And what separates the student who scrapes a C from the one who walks out with an A*? Let's talk about all of that.

What actually is Paper 2?

Paper 2 is a 45-minute exam containing 40 multiple choice questions. Each question has four options: A, B, C, and D. Every correct answer earns one mark, and there's no penalty for guessing wrong. That last point is crucial. Never leave a question blank. Even a random guess gives you a 25% chance, which is infinitely better than 0%.

The paper covers the full Extended syllabus for Cambridge IGCSE Physics (0625). That includes all the Core topics you'd find on Paper 1 plus the supplementary material marked with an "S" in the syllabus guide. Think of it like this: Paper 1 tests you on the ground floor and the first floor of a building. Paper 2 tests you on those same floors but also sends you up to the second floor, where the view is better but the stairs are steeper.

The Extended-only topics that catch people out

Before you even think about technique, you need to know what extra content lives on Paper 2. These Extended-only topics have a habit of showing up as some of the trickiest questions on the paper, and if you haven't revised them, you're essentially handing away marks.

Here's a breakdown of the key areas where Extended goes beyond Core:

The electricity and waves sections tend to carry the most Extended-only questions. If you're short on revision time, those are the areas where an extra hour of practice pays off the most.

Time management: your 40-question sprint

Forty-five minutes for 40 questions works out to just over a minute per question. That sounds comfortable until you hit a calculation that needs three steps or a graph-reading question where you have to interpolate between gridlines. Some questions genuinely take 15 seconds. Others might need two full minutes. The trick is to not let the hard ones steal time from the easy ones.

Here's a time strategy that works well:

1. First pass (25-30 minutes): Go through every question in order. Answer anything you're confident about immediately. If a question looks like it needs more than 90 seconds, circle it on the question paper and move on. Don't agonise. Don't stare at it hoping the answer will appear. Just mark it and keep going.
2. Second pass (10-15 minutes): Return to the circled questions. You'll often find that your brain has been working on them in the background. Give each one your full attention now. If it requires a calculation, do it in the margin. If it requires elimination, cross out the options you know are wrong.
3. Final sweep (last 2-3 minutes): Check your answer sheet. Make sure every question has a response. Look for any accidental double-marks or skipped rows. This is also when you fill in your best guess for anything you genuinely couldn't solve.

The elimination game

Here's something most students don't fully appreciate: you don't always need to know the right answer. You just need to spot the wrong ones.

Every MCQ question gives you four choices. If you can confidently eliminate two of them, you've gone from a 25% guess to a 50/50 coin flip. Eliminate three and you're done. This works especially well on conceptual questions where one or two options contain obvious physics errors.

Take a typical question about transformers. The options might include one where the voltage increases while the current also increases (impossible for an ideal transformer since power must be conserved). Another option might apply the transformer equation to a DC supply (transformers only work with AC). Just recognising those two facts eliminates half the options before you've done any maths.

Some patterns to watch for:

• Unit mismatches: If a question asks for energy in joules and one option gives an answer in watts, that option is wrong regardless of the number.
• Impossible physics: An object accelerating with no net force, current flowing through a complete insulator, efficiency greater than 100%. These are free eliminations.
• Order of magnitude: If you're calculating the current through a household kettle and one option says 0.002 A while another says 10 A, common sense tells you which ballpark is right before you even calculate.
• Distractor reversals: Cambridge sometimes offers an option that uses the right equation but with quantities swapped. If the answer to V = IR should be V = 2 x 5 = 10, one option might show I = V/R = 5/2 = 2.5, which is a real number but answers the wrong question.

Calculation strategies for the Extended paper

IGCSE Physics Paper 2 calculations are quick by design. You won't need to write out pages of working. But you do need to be fast and accurate, because there's no space for "show your working" marks here. Either your answer matches one of the four options or it doesn't.

Keep your equations organised

You're given a formula sheet at the front of the IGCSE paper. Use it. Even if you've memorised every equation, glancing at the sheet confirms you're using the right one and saves you from silly substitution errors under pressure.

But here's what the formula sheet won't tell you: which form of an equation is most efficient for a particular question. Take electrical power. The sheet gives you P = IV, but you should also know P = I²R and P = V²/R by heart. If a question gives you voltage and resistance but not current, jumping straight to P = V²/R saves you an entire step compared to finding I first and then using P = IV.

The "work backwards" trick

Because you already have four possible answers, you can sometimes work backwards. Plug each option into the equation and see which one produces a consistent result. This is particularly useful for questions involving rearranged formulas where you might second-guess yourself on whether to multiply or divide.

Significant figures and rounding

Cambridge typically gives options that are numerically distinct enough that rounding errors won't cause confusion. But occasionally, two options are close together, and sloppy rounding in the middle of a calculation picks the wrong one. A good rule: keep at least three significant figures during your working and only round at the very end.

Worked example: momentum

A 1200 kg car travelling at 15 m/s collides with a stationary 800 kg car. After the collision, they move together. What is their combined velocity?

1. Total momentum before = 1200 x 15 + 800 x 0 = 18 000 kg m/s
2. Total mass after = 1200 + 800 = 2000 kg
3. Combined velocity = 18 000 / 2000 = 9.0 m/s

On the real paper, this might appear as options: A) 6.0 m/s, B) 7.5 m/s, C) 9.0 m/s, D) 15 m/s. Option D is the "forgot to add the masses" trap. Option B might come from a wrong mass ratio. The calculation is straightforward, but under time pressure, it's easy to stumble if you rush.

Worked example: refractive index

Light travels from air into glass. The angle of incidence is 30 degrees and the angle of refraction is 19 degrees. What is the refractive index of the glass?

1. n = sin(angle of incidence) / sin(angle of refraction)
2. n = sin 30 / sin 19 = 0.500 / 0.326 = 1.53

This is a classic IGCSE Extended-only question. Core candidates don't need to use Snell's law, but Extended candidates absolutely do. Make sure your calculator is in degree mode. Every year, some students leave theirs in radians and get a nonsensical answer.

Graph questions: reading them like a story

IGCSE Physics Paper 2 frequently presents graphs and asks you to extract information from them. Velocity-time graphs, I-V characteristics, cooling curves, radioactive decay curves. Each type tells its own story, and your job is to read it.

A velocity-time graph is a good example. The gradient gives acceleration. The area under the line gives distance. A horizontal line means constant velocity. A downward slope means deceleration. If the line crosses the time axis, the object has changed direction. These are the kinds of details that separate right answers from wrong ones, and they don't require any calculation at all, just careful reading.

For decay curves (Extended content), Cambridge often asks you to find the half-life from a graph. Find the starting count rate, halve it, and read across to the time axis. Then double-check by halving again and seeing if the second half-life matches the first. If it does, you've found it. If it doesn't, you may have read the scale wrong.

The tricky question types that sort A* from B

Most IGCSE Physics Paper 2 questions are direct and fair. But a handful each year are designed to separate the top candidates from the rest. These questions don't necessarily require harder physics. They require more careful thinking.

• "Which statement is correct?" questions: These give you four statements and ask which one is true. The danger is that three of them sound plausible. You need precise knowledge, not vague understanding. "A transformer steps up voltage" is true, but "a transformer increases power" is not. The difference is one word.
• Combined-concept questions: These mix two topics together. A question might ask about the efficiency of a motor (energy topic) inside a circuit (electricity topic). You need to pull equations from both areas and combine them. Practice these specifically, because they feel harder than they are.
• Negative or "except" questions: "Which of the following does NOT..." These trip people up because your brain is pattern-matching for correct statements, and suddenly you need to find the wrong one. Underline the word NOT or EXCEPT so you don't forget what you're looking for.
• Proportionality questions: "If the voltage doubles and the resistance stays the same, what happens to the power?" You need to know that P = V²/R, so doubling V means power quadruples, not doubles. These test whether you truly understand the equations or just memorised them.

Common traps and how to sidestep them

Building your revision around past papers

If there's one piece of advice I could give every IGCSE Physics student preparing for Paper 2, it's this: past papers are your best friend. Not your textbook, not your notes, not revision videos. Past papers. They show you exactly what Cambridge expects, how they phrase their questions, and what level of detail earns the mark.

Here's how to use them effectively:

1. Start untimed. Your first few past papers should be about learning, not speed. Take as long as you need. Look up anything you don't know. The goal is to understand the style of questioning.
2. Mark them honestly. Use the mark scheme and examiner report. Don't give yourself the benefit of the doubt. If you picked B and the answer is C, it's wrong, even if you were "nearly" right.
3. Track your weak spots. Keep a simple tally of which topics you're getting wrong. After three or four papers, patterns will emerge. Maybe you keep stumbling on electromagnetic induction. Maybe you're fine on forces but shaky on nuclear physics. That's your revision priority list, written by the exam itself.
4. Move to timed conditions. Once you're scoring above 30/40 untimed, start practising under the real 45-minute constraint. This is where your time management strategy gets tested. You'll quickly learn whether you're a fast starter who slows down or a slow starter who speeds up.
5. Review the examiner reports. Cambridge publishes these for every session, and they're gold. The examiners literally tell you what candidates got wrong and why. If 60% of candidates chose the wrong answer on a particular question, the report explains the misconception. That's free insight into the traps you might fall into.

Test yourself: quick-fire practice

Try these questions under timed conditions. Give yourself no more than 90 seconds each.

1. A force of 20 N is applied to a 4 kg object on a frictionless surface. What is the acceleration?
   A) 0.2 m/s²   B) 5 m/s²   C) 16 m/s²   D) 80 m/s²
2. A transformer has 500 primary turns and 100 secondary turns. The input voltage is 250 V. What is the output voltage?
   A) 25 V   B) 50 V   C) 1250 V   D) 2500 V
3. Which of the following is a correct statement about parallel circuits?
   A) The current is the same through each branch
   B) The total resistance is the sum of individual resistances
   C) The potential difference is the same across each branch
   D) The current does not split at a junction
4. A radioactive sample has a half-life of 6 hours. After 18 hours, what fraction of the original number of undecayed atoms remains?
   A) 1/3   B) 1/6   C) 1/8   D) 1/18

The night before and the morning of

You've done the revision. You've worked through the past papers. The exam is tomorrow. What now?

Don't cram. Seriously, don't. If you haven't learned the transformer equation by the night before, one more hour won't embed it. Instead, do a light review of your formula sheet. Flip through your error log if you kept one. Remind yourself of the two or three things you kept getting wrong and the corrections you learned. Then stop.

On exam morning, check your calculator works and is in degree mode. Bring a spare pen and a sharp pencil for the answer sheet. Arrive early enough that you're not flustered. And remember: 40 questions, 45 minutes, no penalty for guessing. You've got this.

The Extended multiple choice paper rewards students who prepare smartly, not just students who work the hardest. Understanding the format, practising your timing, learning the common traps, and knowing the Extended-only content inside out will put you in the strongest possible position. You've already shown you're capable of the Extended tier. Now go prove it.