Here are exam questions on waves that are common in national exams.
- State two differences between electromagnetic waves and mechanical waves (2 marks)
- Figure 3 show straight waves incident on a divergent lens placed in a ripple tank to reduce its depth.
Complete the diagram to show the waves in both the shallow region and beyond the lens (2 marks)
3. A ship in an ocean sends out an ultra sound whose echo is received after 3 seconds. if the wavelength of the ultra sound in water is 7.5 cm and the frequency of the transmitter is 20 kHz, determine the depth of the ocean. (3 marks)
4. Explain the fact that radiant heat from the sun penetrates a glass sheet while radian heat from burning wood is cut off by the glass sheet. (2 marks)
Question 5
5. (a) figure 5 shows a displacement-time graph for a progressive wave.
(i) State the amplitude of the wave (1 mark)
(ii)Determine the frequency of the wave (4 marks)
(iii) Given that the velocity of the wave is 20 ms-1 , determine it’s wavelength. (3 marks)
(b)Figure 6 shows two identical dippers A and B vibrating in water in phase with each other . The dippers have the same constant frequency and amplitude. The waves produced are observed along the line MN:
It is observed that the amplitude are maximum at points Q and S and minimum at points P and R.
(i) Explain why the amplitude is maximum at Q. (2 marks)
(ii) state why the amplitude is minimum at R (1 mark)
(iii) State what would have happen if the two dippers had different frequencies . ( 1 mark)
6. Figure 7 shows water waves incident on a shallow region of the shape shown with dotted line.
On the same diagram, sketch the wave pattern in and beyond the shallow region (1 mark)
7 . Figure 7 shows standing wave on a string. It is drawn to a scale of 1:5
(a) Indicate on the diagram the wavelength of the standing wave (1 mark)
(b) Determine the wavelength of the wave. (1 mark)