O-LevelPhysicsWaves5054/22 · May/June 2022 · Q815 Marks
(a) Fig. 8.1 shows a ripple tank and the crests of the water wave that is produced in it. [Figure 8.1] The frequency of the water wave is 2.0 Hz and its amplitude is 3.0 mm. (b) (i) The frequency of the wave is increased. Describe how the apparatus shown in Fig. 8.1 is adjusted so that the frequency of the wave is increased. (c) The apparatus shown in Fig. 8.1 can be used to demonstrate refraction. (d) Fig. 8.4 shows a connection to the internet made from a remote station A using a satellite above the Earth's surface. [Figure 8.4] Data is sent between stations A and B using microwaves which travel to and from the satellite. Station B is connected directly to the internet using optical fibre. The speed of microwaves is 3.0 × 10⁸ m/s. Stations A and B are each 560 km from the satellite.
- (a)(i)Calculate the number of crests produced in 1.5 s.[1]
- (a)(ii)The height of the wave is measured from the level of the undisturbed surface of the water. The height of the wave at one point is 0 at time = 0. On Fig. 8.2, draw a graph to show how the height of the wave at this point varies with time.[2]
- (b)(i)The frequency of the wave is increased. Describe how the apparatus shown in Fig. 8.1 is adjusted so that the frequency of the wave is increased.[1]
- (b)(ii)State what happens to the speed and wavelength of the wave as the frequency increases. speed ..., wavelength ...[2]
- (c)(i)State the additional apparatus needed to demonstrate refraction.[1]
- (c)(ii)Draw on Fig. 8.3 to show the refraction of the water wave. Label a boundary where the refraction occurs.[3]
- (d)(i)Calculate the time taken for data to travel from A to B using microwaves.[3]
- (d)(ii)The same data can be sent from A to B in a shorter time along the surface of the Earth using infrared waves to carry the information in optical fibres. State one property that infrared waves and microwaves have in common.[1]
- (d)(iii)Suggest one other advantage of using optical fibres to connect stations A and B directly.[1]
This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.
Mark scheme
Marking points from the official mark scheme (May/June 2022). The mark or mark type is shown in brackets.
- [1] 3
- [1] shape approx. sinusoidal with amplitude 3 mm for the first complete wave (may then change)
- [1] 1 wave taking 0.5 s for first wave shown within half a square OR 1.5 s shown for the number of waves in (a)(i)
- [1] move bar up and down more often (per second) / faster OR make rubber band(s) strong(er) / short(er) / tight(er) / more in number OR use bar of less mass / weight
- [1] speed remains the same
- [1] wavelength decreases
- [1] (piece of) plastic / (piece of) glass / block / plate OR a shallow(er) / deep(er) area / boundary
- [1] diagram showing within the ripple tank: crests parallel to bar hitting boundary with a boundary labelled
- [1] correct refraction of plane crests either towards or away from normal on the same side of the normal OR no direction change if crests are initially parallel to boundary but with a wavelength change
- [1] different wavelength shown before and after refraction and constant before and after (by eye)
- [1] (t =) distance / speed algebraic or numerical seen in any form
- [1] 2 × 560(000) seen or used or 0.0019 (s)
- [1] 0.0037 s
- [1] One of (both): reflect / refract; have same speed (in a vacuum); travel in a vacuum / don't need a medium; are electromagnetic; are transverse; carry energy / cause heating; have larger wavelength / smaller frequency than visible light
- [1] less likely to be hacked / intercepted / greater security OR more channels / better bandwidth possible / more data OR less likely for transmission to be interrupted OR cost of satellites saved / satellites expensive
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →