Question 10
(a)(i) State Two difference between the lens of the human eye and the lens of the camera.
(ii) What is meant by accommodation of the eye?
(b) Explain each of the following terms as applied in sounds:
(i) overtones;
(ii) resonance;
(iii) fundamental note.
(c) Define the principal focus of a diverging lens.
(d) A diverging lens of focal length 10 cm forms an image 5 cm high at a distance of 8 cm from the lens. Calculate the:
(i) objective distance;
(ii) image height;
Observation
Part (a) Candidates performance was below average.
Part (b) Performance was below average.
Part (c) Candidates performance was average.
Part (d) Candidates performance was below average.
The expected answer is:
(a) Factors that affect the frequency of vibrating stretched strings- Length of the string
- Tension in the string
- Mass per unit length of the string
(b)(i) Identification of labelled parts on sonometer
P - Pulley
Q - Bridges
(ii) Functions of a sonometer
Used to
- determine the frequency of tuning forks
- verify the laws of vibrating strings
- measure the frequency of an a.c. supply
(c) Explanation of terms
(i) Fundamental note - the sound of lowest frequency or pitch
(ii) Overtone - a note of frequency higher than the
fundamental frequency of sound.
(iii) Harmonics - notes which are produced by multiples of the
fundamental frequency.
(d)
