Name: ______Year 12 Physics Term 3 Interim Test

Physical constants:

1 amu (u) = 1.66 × 10-27 kg
mp = 1.007 276u
mn = 1.008 665u
n = nano = 10-9 / me = 0.000 549u
e = -1.6 × 10-19 C
1 eV = 1.6 × 10-19 J
1 amu = 931.5MeV / h = 6.626 × 10-34 Js
R = 1.1 × 107 m-1
c = 3 × 108 m/s

1. For a single photon of red light of wavelength λ=620nm, determine:

(a) the frequency, f:

(1 Mark)

(b) the energy in Joules:

(1 Mark)

(c) the energy in eV:

(1 Mark)

2. 0V e- + 10V

An electron is ejected from the cathode shown with approximately 0J of energy.

(a) Determine the energy of the electron has it impacts the anode in eV:

(1 Mark)

(b) What is the velocity of the electron at the anode.

(2 Marks)

3. An intense beam of red light of wavelength λ=620nm falls onto a metal of Work function W=2.5eV. Fully explain what you expect to happen with regard to the emission of electrons under these circumstances.

(1 Mark)

4. A beam of violet light of wavelength λ=400nm falls on the same metal of Work function W=2.5eV. What is the maximum kinetic energy of the emitted electrons in eV.

(1 Mark)

5. An electron makes a transition from level n=4 to level n=2 in Hydrogen. What is the wavelength of the emitted photon.

(1 Mark)

6. What is the energy of the n=6 energy level of the Hydrogen atom in Joules.

(1 Mark)

7. A photon of energy 7eV is incident on a gas if atoms possessing the following energy level structure.

7eV

5eV

0eV

What are the energy levels of all the observable photons coming from this gas in eV.

(1.5 Marks)

8. A beam of many electrons of energy 8eV is incident on a gas of the same atoms as in Question 7 with the same energy level structure. What are the possible energies of the electrons emerging from the gas in eV.

(1.5 Marks)

9. A radioactive source emits radiation (into the page) which splits into three beams (bending up, straight, and down)when travelling perpendicularly to a magnetic field B running to the right across the page.

Using three symbols, clearly label the particles making the three dots on the detector.

(1.5 Marks)

10. Balance the following equations:

(5 Marks)

11. A radioactive sample shows the following Activity pattern over time.

Time (s) / Activity (s-1)
0 / 1024
1
2
3
4 / 64

(a) Accurately complete the Activity column of the table.

(1.5 Marks)

(b) Accurately determine your best estimate of the initial number of atoms of the radioactive substance present at time t=0.

(2 Marks)

12. A radioactive sample initially has 106 atoms at time t=0, and has 104 atoms after 3 days. What is the half life of the substance.

(3 Marks)

13.

(a) Explain what this process represents and briefly state two possible applications.

(2 Marks)

14. One possible fusion reaction is

The mass of deuterium (21H) = 2.01355u

The mass of helium-3 (32He) = 3.01603u

The mass of helium-4 (42He) = 4.002603u

(a) Ignoring the electrons, calculate the mass defect in amu for this reaction.

(2 Marks)

(b) Calculate the energy release in Joules for this reaction.

(2 Marks)

32 / A+ / 100%
31.5 / A+ / 98%
31 / A+ / 97%
30.5 / A+ / 95%
30 / A / 94%
29.5 / A / 92%
29 / A / 91%
28.5 / A- / 89%
28 / A- / 88%
27.5 / A- / 86%
27 / B+ / 84%
26.5 / B+ / 83%
26 / B+ / 81%
25.5 / B+ / 80%
25 / B / 78%
24.5 / B / 77%
24 / B / 75%
23.5 / B / 73%
23 / B / 72%
22.5 / B- / 70%
22 / B- / 69%
21.5 / B- / 67%
21 / B- / 66%
20.5 / C+ / 64%
20 / C+ / 63%
19.5 / C+ / 61%
19 / C+ / 59%
18.5 / C / 58%
18 / C / 56%
17.5 / C / 55%
17 / C / 53%
16.5 / C / 52%
16 / C- / 50%
15.5 / C- / 48%
15 / C- / 47%
14.5 / C- / 45%
14 / D+ / 44%