Module Workbook

Module 19: Physics

Cathode rays, X-rays, photoelectricity.

Use this workbook to practice core KCSE communication skills and record evidence of progress.

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SECTION: PHYSICS

MODULE: 19

Part A: Units

1. Cathode rays and cathode ray tube

a. Properties of cathode rays

b. Cathode ray tube

c. Properties of cathode rays (repeated)

d. C.R.O and T.V. tubes

e. Uses of CRO

f. Problems on CRO

2. X rays

a. Production of X rays

b. X ray tube

c. Energy changes in an X ray tube

d. Properties of X rays

e. Soft and hard X rays

f. Dangers of X rays and precautions

g. Uses of X rays, problems on X rays

3. Photoelectric effect

a. Define: threshold frequency, work function and electron volt

b. Factors affecting photoelectric emission

c. Energy of photons

d. Einstein equation hf = hf0 + 1/2 mv^2

e. Applications of photoelectric effect

f. Problems on photoelectric emissions

Part B: Project

Connect cathode rays, X rays, and photoelectric effect to real devices.

Project Title: Electron Emission and Radiation

Objective: Explain how cathode rays and X rays are produced and applied.

Project Instructions:

1. Describe a cathode ray tube and its uses.
2. Explain how X rays are produced and list two uses.
3. Identify dangers of X rays and safety precautions.
4. Summarize the photoelectric effect with one application.
5. Solve one numerical problem from CRO or photoelectric effect.
6. Consult your coach where necessary.

Evidence to Submit:

• Cathode ray tube summary.
• X ray uses and safety notes.
• Photoelectric application and solution.

Submission

Part C: Training Others

Teach a peer about CRTs, X rays, and photoelectric effect.

Guidance:

• Explain how cathode rays are produced.
• Discuss X ray production and safety.
• Outline the photoelectric effect in simple terms.

Reflection:

• What did the learner understand well?
• Which topic needed more clarity?
• What support do you need from your coach?

Submission

Part D: Assessment

Competency Levels:

1 = Expectations not met

2 = Partially met

3 = Satisfactorily met

4 = Excellently met

Coach assessment: Learner completes the self-assessment using the 1-4 scale. The coach prepares a short quiz or conversation (outside the system if needed) and assigns the coach score.

Self-assessment:

• Cathode rays and CRO:
• X ray production and safety:
• Photoelectric effect and applications:

Coach assessment:

• Cathode rays and CRO:
• X ray production and safety:
• Photoelectric effect and applications:

Submission

Ready for the next module?

Keep your learning rhythm steady and record your reflections as you progress.

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