Each round shows four options. Three of them belong to the group in the question. One does not. You tap the one that does not belong.
The groups cover the whole subject: SI units, the four fundamental forces, quarks and leptons, vectors and scalars, optics, circuits, thermodynamics and the physicists themselves.
The traps are the point. The newton feels like a base unit and is not one. The muon feels like a quark and is a lepton. Friction feels like a fundamental force, but it is electromagnetism between two surfaces. Each round ends with one line that explains the answer.
How to play
Each round asks one question, for example "Which of these is NOT an SI base unit?".
Read the question. Then tap the option that does not belong.
You get one pick for each round. There are no second guesses.
The quiz marks your answer immediately. It also gives one line that explains the answer.
You start with three lives. The hearts in the top bar show the lives that you have.
A correct answer gives one point. A wrong answer costs one life.
A round that costs a life gives no points. The quiz continues with the next round.
The run ends when you lose the third life. It also ends when you play all the rounds.
Select "Review rounds" on the result screen to see each round that you played.
What counts in this quiz
33 groups from physics. One run can use all of them. The rounds, the options and the impostor are drawn fresh every run.
Every option is clearly in the group or clearly out of it. No round has two possible answers.
The unit rounds follow the SI, the international system of units. The SI has exactly seven base units.
The particle rounds follow the Standard Model. It sorts particles into quarks, leptons and force carriers.
Your score is the number of correct answers. The maximum score is 33 — every round in the quiz.
A wrong answer costs one life. You keep the points that you have.
The timer counts up from your first pick. It only separates equal scores on the leaderboard.
What's not included — and why
Physics that physicists still argue about is not used, on either side of a round.
The graviton is never a force carrier here. The particle is a prediction, and nobody has found one.
A quark is never a part of an atom here. A quark is a part of a proton, which is one step further down.
An X-ray is never nuclear radiation here. X-rays come from electrons, not from a nucleus.
No formulas. The quiz asks what belongs to what. It does not ask you to calculate.
Good to know
The SI has seven base units. Every other unit in physics is built from those seven, so the newton is a kilogram metre per second squared.
Friction is not a fundamental force. It is electromagnetism between the atoms of two surfaces that touch.
Stephen Hawking never won the Nobel Prize in Physics. The prize needs a confirmed measurement, and nobody has measured the radiation named after him.
Quarks come in six flavours with strange names: up, down, charm, strange, top and bottom. The names carry no meaning. Physicists chose them because they were free.