Physics 11th Chap 14 : Topic 7 - Maryam Publications

Physics Chapter 14 : Topic 7

Quark Composition of Protons and Neutrons

1 / 30

According to the quark model, a proton is composed of:

A) One up quark and two strange quarks

B) Two down quarks and one up quark

C) Three up quarks

D) Two up quarks and one down quark

2 / 30

The quark composition of a neutron is:

A) $\mathbf{udd}$

B) $\mathbf{ddd}$

C) $\mathbf{uuu}$

D) $\mathbf{uud}$

3 / 30

The total electric charge of a proton can be calculated from:

A) $\mathbf{( + \ e) + ( + \ e) + ( - \ e)}$

B) $\mathbf{( - \ 2/3\ e) + ( - \ 2/3\ e) + ( + \ 1/3\ e)}$

C) $\mathbf{( + \ 2/3\ e) + ( + \ 2/3\ e) + ( - \ 1/3\ e)}$

D) $\mathbf{( + \ 1/3\ e) + ( + \ 1/3\ e) + ( - \ 2/3\ e}\mathbf{)}$

4 / 30

The net charge of a neutron is zero because:

A) It contains only neutral quarks.

B) Its quark charges cancel each other.

C) It contains no quarks.

D) Its mass removes its charge.

5 / 30

Which combination represents a proton?

A) $\mathbf{u + d + d}$

B) $\mathbf{u + u + d}$

C) $\mathbf{d + d + d}$

D) $\mathbf{u + s + d}$

6 / 30

The charge of an up quark is:

A) $\mathbf{+ \ 2/3\ e}$

B) $\mathbf{- \ 1/3\ e}$

C) $\mathbf{- \ 2/3\ e}$

D) $\mathbf{+ \ 1/3\ e}$

7 / 30

Which combination represents a neutron?

A) $\mathbf{u + u + d}$

B) $\mathbf{d + s + s}$

C) $\mathbf{u + u + u}$

D) $\mathbf{u + d + d}$

8 / 30

The charge of a down quark is:

A) $\mathbf{- \ 1/3\ e}$

B) $\mathbf{- \ 2e}$

C) $\mathbf{+ \ 1/3\ e}$

D) $\mathbf{+ \ 2/3\ e}$

9 / 30

A particle made of two up quarks and one down quark will have charge:

A) $\mathbf{- \ e}$

B) $\mathbf{+ \ 2e}$

C) $\mathbf{+ \ e}$

D) Zero

10 / 30

A particle made of one up quark and two down quarks will have charge:

A) $\mathbf{+ \ 2e}$

B) Zero

C) $\mathbf{- \ e}$

D) $\mathbf{+ \ e}$

11 / 30

Protons and neutrons are classified as:

A) Leptons

B) Mesons

C) Photons

D) Baryons

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A baryon is a particle made of:

A) 1 quark and 1 antiquark

B) Three quarks

C) Two quarks

D) One quark

13 / 30

The difference between a proton and neutron is mainly due to:

A) Absence of strong force

B) Presence of electrons

C) Different arrangement of up and down quarks

D) Different number of quarks

14 / 30

Which statement about proton and neutron composition is correct?

A) Neutron contains no quarks

B) Proton has more down quarks than neutron

C) Neutron has more down quarks than proton

D) Proton and neutron contain identical quarks in identical numbers

15 / 30

The charge of a proton arises because:

A) Neutrons create positive charge.

B) Quarks have fractional charges that add to $\mathbf{+ \ e}$.

C) Quarks have no charge.

D) Only electrons contribute charge.

16 / 30

If the down quark charge is $\mathbf{- \ 1/3\ e}$, then two down quarks together have charge:

A) $\mathbf{+ \ 2/3\ e}$

B) $\mathbf{- \ 1/3\ e}$

C) $\mathbf{- \ 2/3\ e}$

D) $\mathbf{+ \ 1e}$

17 / 30

If two up quarks are present in a proton, their combined charge is:

A) $\mathbf{+ \ 1/3\ e}$

B) $\mathbf{- \ 4/3\ e}$

C) $\mathbf{+ \ 2/3\ e}$

D) $\mathbf{+ \ 4/3\ e}$

18 / 30

Which quark combination produces a neutral baryon?

A) $\mathbf{udd}$

B) $\mathbf{uuu}$

C) $\mathbf{udd}$

D) $\mathbf{udd}$ with extra electron

19 / 30

A proton changes into a neutron. Which quark change occurs?

A) An up quark changes into a down quark.

B) All quarks disappear.

C) A quark changes into a photon.

D) A down quark changes into an up quark.

20 / 30

A neutron changes into a proton during beta-minus decay. The quark-level change is:

A) $\mathbf{u\ }\overset{\mathbf{\ \ \ \ \ \ \ \ \ \ \ \ }}{\rightarrow}\mathbf{\ d}$

B) $\mathbf{d\ }\overset{\mathbf{\ \ \ \ \ \ \ \ \ \ \ \ }}{\rightarrow}\mathbf{\ c}$

C) $\mathbf{d\ }\overset{\mathbf{\ \ \ \ \ \ \ \ \ \ \ \ }}{\rightarrow}\mathbf{\ u}$

D) $\mathbf{u\ }\overset{\mathbf{\ \ \ \ \ \ \ \ \ \ \ \ }}{\rightarrow}\mathbf{\ s}$

21 / 30

Which particles have the same quark content?

A) Proton and neutron

B) Neutron and photon

C) Proton and electron

D) Proton and positron

22 / 30

A proton contains how many up quarks?

A) Zero

B) One

C) Two

D) Three

23 / 30

A neutron contains how many down quarks?

A) Zero

B) Three

C) Two

D) One

24 / 30

Which statement is correct about the masses of proton and neutron?

A) Their masses are mainly related to energy of quark interactions.

B) Proton has no quarks.

C) Their masses come only from quark rest masses.

D) Quarks have no role in their mass.

25 / 30

A particle has composition $\mathbf{uuu}$. Its charge would be:

A) $\mathbf{+ \ e}$

B) $\mathbf{- \ e}$

C) Zero

D) $\mathbf{+ \ 2e}$

26 / 30

A particle has composition $\mathbf{ddd}$. Its charge would be:

A) $\mathbf{+ \ e}$

B) $\mathbf{+ \ 2e}$

C) Zero

D) $\mathbf{- \ e}$

27 / 30

Which statement explains why a neutron is neutral?

A) The positive and negative fractional quark charges cancel.

B) It contains no charged particles.

C) It contains only electrons.

D) It has no mass.

28 / 30

The quark model explains that:

A) Electrons are made of protons.

B) Protons and neutrons are made of smaller particles called quarks.

C) Photons contain quarks.

D) Protons are fundamental particles with no structure.

29 / 30

Which of the following correctly compares proton and neutron?

A) Proton: $\mathbf{uud}$, Neutron: $\mathbf{udd}$

B) Both: $\mathbf{uuu}$

C) Proton: $\mathbf{udd}$, Neutron: $\mathbf{uud}$

D) Both: $\mathbf{ddd}$

30 / 30

The reason protons and neutrons are not considered fundamental particles is that:

A) They have no charge.

B) They have no mass.

C) They are made of quarks.

D) They cannot interact.

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