Question 22M.2.HL.TZ1.c
| Date | May 2022 | Marks available | [Maximum mark: 2] | Reference code | 22M.2.HL.TZ1.c |
| Level | HL | Paper | 2 | Time zone | TZ1 |
| Command term | Show that | Question number | c | Adapted from | N/A |
Two loudspeakers A and B are initially equidistant from a microphone M. The frequency and intensity emitted by A and B are the same. A and B emit sound in phase. A is fixed in position.
B is moved slowly away from M along the line MP. The graph shows the variation with distance travelled by B of the received intensity at M.
B is placed at the first minimum. The frequency is then changed until the received intensity is again at a maximum.
Show that the lowest frequency at which the intensity maximum can occur is about 3 kHz.
Speed of sound = 340 m s−1
[2]
«» = 13 cm ✓
«» 2.6 «kHz» ✓
Allow ½ of wavelength from (b) or data from graph for MP1.
Allow ECF from MP1.
This was a "show that" question that had enough information for backwards working. Examiners were looking for evidence of using the wavelength from (b) or information from the graph to determine wavelength followed by a correct substitution and an answer to more significant digits than the given result.
