Question 21N.2.HL.TZ0.8
| Date | November 2021 | Marks available | [Maximum mark: 9] | Reference code | 21N.2.HL.TZ0.8 |
| Level | HL | Paper | 2 | Time zone | TZ0 |
| Command term | Determine, Show that, State | Question number | 8 | Adapted from | N/A |
State what is meant by the Doppler effect.
[2]
the change in the observed frequency ✓
when there is relative motion between the source and the observer ✓
Do not award MP1 if they refer to wavelength.
A plate performs simple harmonic oscillations with a frequency of 39 Hz and an amplitude of 8.0 cm.
Show that the maximum speed of the oscillating plate is about 20 m s−1.
[2]
use of ✓
maximum speed is «m s−1» ✓
Award [2] for a bald correct answer.
Sound of frequency 2400 Hz is emitted from a stationary source towards the oscillating plate in (b). The speed of sound is 340 m s−1.
Determine the maximum frequency of the sound that is received back at the source after reflection at the plate.
[2]
frequency at plate «Hz»
at source «Hz» ✓
Award [2] marks for a bald correct answer.
Award [1] mark when the effect is only applied once.
The graph shows the variation with diffraction angle of the intensity of light after it has passed through four parallel slits.
The number of slits is increased but their separation and width stay the same. All slits are illuminated.
State what will happen to the angular position of the primary maxima.
[1]
stays the same ✓
State what will happen to the width of the primary maxima.
[1]
decreases ✓
State what will happen to the intensity of the secondary maxima.
[1]
decreases ✓