13 Jun 2026

Particle Physics Standard Problems

Standard competitive exam problems in particle physics with answer key.

particle-physics gate-2024 csir-net-2023 jest-2022

These are original standard problems based on frequently tested competitive-exam patterns.

Q: A proton has quark content
A: $uud$
B: $udd$
C: $u\bar d$
D: $sss$
ANSWER: A
SOURCE: GATE 2024 style
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Q: Lepton number is conserved in
A: ordinary weak interactions
B: all arbitrary mathematical transformations
C: only electromagnetic interactions
D: no beta decay process
ANSWER: A
SOURCE: CSIR-NET 2023 style
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Q: The photon is the gauge boson of
A: strong interaction
B: electromagnetic interaction
C: weak charged current only
D: gravity in the Standard Model
ANSWER: B
SOURCE: JEST 2022 style
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Q: Baryons are particles made of
A: one quark and one antiquark
B: three quarks
C: two leptons
D: photons only
ANSWER: B
SOURCE: GATE 2021 style
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Q: The electric charge of an up quark is
A: $+2e/3$
B: $-e/3$
C: $+e$
D: $0$
ANSWER: A
SOURCE: CSIR-NET 2020 style
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Q: A charged pion $\pi^+$ has quark content
A: $u\bar d$
B: $d\bar u$
C: $uud$
D: $s\bar s$
ANSWER: A
SOURCE: GATE style
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Q: The strong interaction is mediated by
A: photons
B: gluons
C: $W^\pm$ only
D: gravitons
ANSWER: B
SOURCE: CSIR-NET style
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Q: Strangeness is not conserved in
A: strong interactions
B: electromagnetic interactions
C: weak interactions
D: elastic pion scattering by strong force
ANSWER: C
SOURCE: JEST style

Problem Sheet Standard MCQs