G12 ADVANCED MOCK TEST 4

Physics — End of Term Mock Test 4

Obj 16–20  ·  25 Questions  ·  45 Minutes  ·  1 mark each

45:00
TIME REMAINING
0 / 25 answered
Q1Obj 17

An electron orbits a nucleus in a Bohr orbit with radius r. If the electron's de Broglie wavelength is λ, what is the value of n for the first stable orbit?

An = r / λ
Bn = 2πr / λ
Cn = λ / 2πr
Dn = λ / r
Q2Obj 18

The nucleus of one of the isotopes of nickel is \(^{60}_{28}\text{Ni}\). Which line correctly describes a neutral atom of this isotope?

A28 protons, 32 neutrons, 28 orbital electrons
B28 protons, 60 neutrons, 28 electrons
C60 protons, 28 neutrons, 28 electrons
D60 protons, 32 neutrons, 32 electrons
Q3Obj 19

The mass defect of a nucleus is defined as:

AThe mass of the nucleus
BThe difference between the mass of the nucleus and the sum of the masses of its constituent nucleons
CThe binding energy divided by c²
DBoth B and C
Q4Obj 20

Which statement correctly explains why energy is released in nuclear fusion of light nuclei?

AThe products have lower binding energy per nucleon
BThe products have higher binding energy per nucleon
CThe products have fewer nucleons
DThe products are radioactive
Q5Obj 17

In the Bohr model combined with de Broglie’s idea, what physical concept explains why the electron cannot have arbitrary orbit radii?

AElectron's charge quantization
BElectron’s wavefunction must be single-valued and continuous
CElectron’s energy is proportional to orbit circumference
DElectron’s speed is fixed by the nucleus charge
Q6Obj 16

An electron transitions from a higher energy level E_i to a lower energy level E_f, emitting a photon of wavelength 500 nm. If E_i = -3.2 × 10⁻¹⁹ J, calculate E_f. (h = 6.63 × 10⁻³⁴ J·s, c = 3.00 × 10⁸ m/s)

A-7.3 × 10⁻²⁰ J
B-5.0 × 10⁻¹⁹ J
C-2.5 × 10⁻¹⁹ J
D-4.0 × 10⁻¹⁹ J
Q7Obj 20

Which statement correctly explains why energy is released in nuclear fission of heavy nuclei?

AThe fission fragments have lower binding energy per nucleon than the original nucleus
BThe fission fragments have higher binding energy per nucleon than the original nucleus
CThe total number of nucleons decreases
DThe fission fragments are lighter elements
Q8Obj 17

Given an electron of mass 9.11 × 10⁻³¹ kg moving in a Bohr orbit of radius 5.29 × 10⁻¹¹ m with speed 2.19 × 10⁶ m/s, calculate the number of de Broglie wavelengths fitting in the orbit circumference.

A1
B2
C3
D4
Q9Obj 17

What does the equation 2πr = nλ represent in the Bohr model with de Broglie waves?

AThe electron's orbit radius equals the de Broglie wavelength times n
BThe electron's orbit circumference contains exactly n wavelengths of the electron's matter wave
CThe electron's wavelength is inversely proportional to the orbit radius
DThe electron's energy levels are continuous
Q10Obj 19

Which statement about the strong nuclear force is correct?

AIt is always attractive at all distances
BIt is repulsive at very short distances and attractive at slightly larger distances
CIt acts only between protons
DIt is weaker than the electrostatic force at nuclear distances
Q11Obj 20

Which nucleus is the most stable based on binding energy per nucleon?

A\(^{2}_{1}\text{H}\) (deuterium)
B\(^{4}_{2}\text{He}\) (helium-4)
C\(^{56}_{26}\text{Fe}\) (iron-56)
D\(^{238}_{92}\text{U}\) (uranium-238)
Q12Obj 19

Which of the following correctly describes the strong nuclear force?

ALong-range, acts only on charged particles
BShort-range, acts on all nucleons, attractive at nuclear distances
CShort-range, acts only on protons
DLong-range, acts on all particles with mass
Q13Obj 19

The mass of a proton is 1.00728 u and the mass of a neutron is 1.00867 u. The mass of a \(^{4}_{2}\text{He}\) nucleus is 4.00150 u. What is the mass defect of the helium nucleus in atomic mass units?

A0.00150 u
B0.02920 u
C0.03040 u
D0.05290 u
Q14Obj 19

A nucleus has a mass defect of 5.0 × 10⁻²⁹ kg. The binding energy of this nucleus is:

A4.5 × 10⁻¹² J
B5.0 × 10⁻²⁹ J
C1.5 × 10⁻¹¹ J
D9.0 × 10⁻¹² J
Q15Obj 16

An electron in a hydrogen atom transitions from the n=3 level to the n=2 level. The energy of the n=3 level is -1.51 eV and that of the n=2 level is -3.40 eV. Calculate the wavelength of the emitted photon. (Take h = 6.63×10⁻³⁴ Js, c = 3.00×10⁸ m/s, 1 eV = 1.60×10⁻¹⁹ J)

A656 nm
B486 nm
C434 nm
D410 nm
Q16Obj 19

The strong nuclear force acts between:

AProtons only
BNeutrons only
CProtons and electrons
DAll nucleons (proton-proton, neutron-neutron, proton-neutron)
Q17Obj 20

The binding energy per nucleon of \(^{2}_{1}\text{H}\) (deuterium) is 1.1 MeV. The binding energy per nucleon of \(^{4}_{2}\text{He}\) is 7.1 MeV. When two deuterium nuclei fuse to form helium-4, the energy released is approximately:

A6.0 MeV
B8.0 MeV
C24.0 MeV
D28.4 MeV
Q18Obj 20

In the reaction \(^{1}_{1}\text{p} + ^{2}_{1}\text{H} \rightarrow ^{3}_{2}\text{He} + Q\), using masses: proton = 1.00728 u, ²H = 2.01355 u, ³He = 3.01493 u. What is Q?

A5.0 MeV
B5.5 MeV
C6.0 MeV
D6.5 MeV
Q19Obj 18

Which two nuclei contain the same number of neutrons?

A\(^{12}_{6}\text{C}\) and \(^{14}_{6}\text{C}\)
B\(^{16}_{7}\text{N}\) and \(^{15}_{8}\text{O}\)
C\(^{23}_{11}\text{Na}\) and \(^{24}_{12}\text{Mg}\)
D\(^{32}_{14}\text{Si}\) and \(^{32}_{15}\text{P}\)
Q20Obj 17

If an electron in a Bohr orbit has a de Broglie wavelength λ, what would happen if the circumference 2πr was not an integer multiple of λ?

AThe electron would emit continuous radiation
BThe electron's wave would interfere destructively, making the orbit unstable
CThe electron would gain infinite energy
DThe electron would remain stable but at a different radius
Q21Obj 19

Which of the following is evidence that the strong nuclear force must exist?

ANuclei can emit alpha particles
BProtons in a nucleus do not fly apart despite electrostatic repulsion
CElectrons orbit the nucleus
DRadioactive decay occurs spontaneously
Q22Obj 20

A nucleus has a binding energy of 492 MeV and contains 56 nucleons. Its binding energy per nucleon is:

A492 MeV
B56 MeV
C8.79 MeV
D27,552 MeV
Q23Obj 18

The mass number A of a nucleus is defined as:

AThe number of protons only
BThe number of neutrons only
CThe total number of protons and neutrons
DThe number of electrons in the atom
Q24Obj 19

The mass defect of \(^{56}_{26}\text{Fe}\) is 0.5290 u. Using 1 u = 1.661 × 10⁻²⁷ kg, the mass defect in kg is:

A5.29 × 10⁻²⁸ kg
B8.79 × 10⁻²⁸ kg
C3.19 × 10⁻²⁷ kg
D1.66 × 10⁻²⁷ kg
Q25Obj 17

Why does the Bohr model require the electron orbit circumference to be an integer multiple of the de Broglie wavelength?

ATo maximize the electron's kinetic energy
BTo ensure the electron’s wavefunction is continuous and does not destructively interfere
CTo allow the electron to move faster than the speed of light
DTo maintain a fixed orbit radius regardless of energy level