Podcast
Questions and Answers
Evaluation is the most important process in the assessment of candidates.
Evaluation is the most important process in the assessment of candidates.
True
What may happen if the evaluation policy leaks to the public?
What may happen if the evaluation policy leaks to the public?
Derailment of the examination system and possible impact on the lives and futures of millions of candidates.
What should evaluators do when they encounter a correct but unconventional answer?
What should evaluators do when they encounter a correct but unconventional answer?
How many answer books should an examiner evaluate per day in main subjects?
How many answer books should an examiner evaluate per day in main subjects?
Signup and view all the answers
Which of the following is a common error made by examiners?
Which of the following is a common error made by examiners?
Signup and view all the answers
Marks must be awarded in the right-hand margin for each part of a question.
Marks must be awarded in the right-hand margin for each part of a question.
Signup and view all the answers
Study Notes
General Instructions
- This document contains 12 questions. All questions are compulsory.
- The document is divided into three sections: A, B, and C.
- Section A comprises questions 1-3, each worth 2 marks.
- Section B has questions 4-11, each worth 3 marks.
- Question 12 is a case study question, worth 5 marks.
- There are internal choices in some questions.
- Students can use log tables, but calculators are not permitted.
- Important constants are included: c = 3 x 10⁸ m/s, h = 6.63 x 10⁻³⁴ Js, e = 1.6 x 10⁻¹⁹ C, μ₀ = 4π x 10⁻⁷ Tm A⁻¹, ε₀ = 8.854 x 10⁻¹² C² N⁻¹ m⁻², (4πε₀)⁻¹ = 9 x 10⁹ N m² C⁻². Also, masses of electron, neutron, and proton are provided.
- The time allotted for reading the paper before writing answers is 15 minutes.
Section A
-
Question 1:
- (a) requires a graph showing the variation of the number of scattered alpha particles with scattering angle in a Geiger-Marsden experiment, and two conclusions to be drawn from this graph.
- (b) requires plotting graphs to show the variation of photoelectric current with collector plate potential, given varying frequencies and intensities of incident radiation (graphs for the same intensity but different frequencies and the same frequency but different intensities).
-
Question 2: Explain the difference between intrinsic and extrinsic semiconductors. Explain why an extrinsic semiconductor is electrically neutral despite having unequal electron and hole densities.
-
Question 3: Draw and label energy band diagrams for n-type and p-type semiconductors at a temperature greater than absolute zero, showing donor and acceptor energy levels. Provide the significance of these levels.
Section B
- Question 4:
- (a) Calculate the distance of the first minimum and the second maximum in a diffraction pattern created by a parallel beam of light of wavelength 600 nm incident on a slit of width 0.2 mm. The observation is made on a screen 1 meter away.
- (b) Two lenses with different refractive indices and curvatures are in contact. Calculate the ratio of their powers and the nature of the combined lens.
Section C
- Question 12: The principle of superposition is used to understand the interference of light waves. Given a set of waves (y₁=a sin ωt, y₂=a sin 2ωt, y₃=a sin (2ωt+φ), y₄=a sin(4ωt+π/2)), determine which pairs of waves will lead to interference.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz covers the Geiger-Marsden experiment and the behavior of alpha particles under scattering. It includes multiple sections with questions that test knowledge of scattering angles, graph interpretation, and relevant physical constants. Prepare to apply your understanding of particle physics concepts.
