Two pulses travel towards each other along a rope. At one instant an upward pulse of amplitude $3.0\ \text{cm}$ overlaps a downward pulse of amplitude $1.0\ \text{cm}$ at the same point.

Plane water waves travel from deep water into shallow water. The frequency of the waves is $8.0\ \text{Hz}$. The speed is $0.32\ \text{m s}^{-1}$ in deep water and $0.20\ \text{m s}^{-1}$ in shallow water.

Monochromatic light of wavelength $640\ \text{nm}$ is incident normally on a single rectangular slit of width $0.20\ \text{mm}$.

Monochromatic light is incident normally on a single narrow rectangular slit. The axes show intensity $I$ against angular displacement $\theta$ from the central axis.

Two diffraction patterns are produced using the same monochromatic light and the same slit spacing. Pattern A is produced by $5$ equally illuminated slits. Pattern B is produced by $20$ equally illuminated slits.

Plane water waves travel from a deep region into a shallow region of a ripple tank. The diagram shows wavefronts and one ray at the boundary.

Plane water waves are incident normally on three apertures of different widths. The same wave source is used in each case.

A ray of light in glass of refractive index $1.50$ is incident on a glass-air boundary at an angle of incidence of $46.0^\circ$. The refractive index of air is $1.00$.

A laser is directed normally at a double slit. The slit separation is $0.250\ \text{mm}$ and the screen is $2.40\ \text{m}$ from the slits. The distance across $10$ adjacent fringe spacings on the screen is $60.0\ \text{mm}$.

A laser is incident normally on a pair of identical slits of finite width. The observed pattern on a distant screen is a set of interference fringes whose brightness decreases away from the centre.

Monochromatic light of wavelength $532\ \text{nm}$ is incident normally on a diffraction grating with $600$ lines per millimetre.

A student measures the angles of incidence $i$ in air and refraction $r$ in a transparent block. The graph shows $\sin i$ plotted against $\sin r$.

Two pulses travel towards each other along a string. The graph shows the displacement that each pulse would produce separately at the same instant.

Two coherent loudspeakers emit sound of wavelength $0.34\ \text{m}$. A microphone is moved to different positions in front of the speakers. The table gives the distances from each speaker to the microphone.

Coherent monochromatic light is incident normally on arrays with different numbers $N$ of equally spaced slits. The slit spacing is the same for all arrays. The graph compares the intensity patterns.

White light is incident normally on a diffraction grating with $500$ lines per millimetre. The diagram shows the central maximum and the first-order spectra on both sides.

White light is incident normally on a diffraction grating with slit spacing $2.00\times10^{-6}\ \text{m}$. Consider blue light of wavelength $450\ \text{nm}$ and red light of wavelength $650\ \text{nm}$ in the first-order spectrum.

A ray of light travels inside a semicircular glass block and meets the flat glass-air boundary at different angles of incidence. The table shows observations at the boundary.

Monochromatic laser light of wavelength $640\ \text{nm}$ is incident normally on a single rectangular slit. The screen is $2.00\ \text{m}$ from the slit. The graph shows the intensity pattern on the screen.

A double slit with finite slit width is illuminated by monochromatic light at normal incidence. The graph shows the observed intensity pattern on a distant screen.

A diffraction grating has $600$ lines per millimetre. Monochromatic light is incident normally on the grating. The table gives the measured angles of the bright maxima.

Plane water waves in a ripple tank travel from deep water into a shallow region at an angle to the boundary. The incident wavefronts are shown before reaching the boundary.

A radio transmitter is on one side of a hill. Two receivers are placed at the same distance from the transmitter on the other side of the hill. Receiver A uses a signal of wavelength $850\ \text{m}$ and receiver B uses a signal of wavelength $0.30\ \text{m}$.

Two pulses travel towards each other along the same rope. Pulse P has upward displacement and pulse Q has downward displacement. The rope is assumed to obey the principle of superposition.

A student investigates single-slit diffraction using the same laser and different slit widths. The table gives the measured angular width of the central maximum, from the first minimum on one side to the first minimum on the other side.

A student investigates light travelling from air into a transparent plastic block. The refractive index of air is $1.00$. The speed of light in air may be taken as $3.00\times 10^8\ \text{m s}^{-1}$. For the first interface, the angle of refraction in the plastic is $31.0^\circ$.

Two coherent loudspeakers, S1 and S2, are connected to the same signal generator. A microphone is placed at point P. The speed of sound in air is $340\ \text{m s}^{-1}$. The loudspeakers emit sound of frequency $500\ \text{Hz}$.

A student uses a laser and a double slit to determine the wavelength of light. The slit separation is $0.250\ \text{mm}$ and the screen is $2.40\ \text{m}$ from the slits. The distance across ten adjacent fringe spacings is measured as $48.0\ \text{mm}$.

Monochromatic laser light of wavelength $632\ \text{nm}$ is incident normally on a single rectangular slit of width $0.180\ \text{mm}$. The diffraction pattern is observed on a screen $3.20\ \text{m}$ from the slit.

A diffraction grating has $500$ lines per millimetre. It is illuminated at normal incidence by monochromatic light of wavelength $520\ \text{nm}$.

A laser illuminates two different aperture arrays at normal incidence. Array X has $2$ equally spaced slits and array Y has $8$ equally spaced slits. In both cases the slit separation and the illumination of each slit are the same.

A double slit is illuminated normally by monochromatic light of wavelength $600\ \text{nm}$. The slit separation is $0.300\ \text{mm}$ and each slit has width $0.0600\ \text{mm}$. A screen is placed far from the slits.

White light is incident normally on a diffraction grating. The grating spacing is $1.67\times10^{-6}\ \text{m}$. Take the visible wavelength range to be from $400\ \text{nm}$ to $700\ \text{nm}$.

A student measures the wavelength of a laser using a diffraction grating. The grating has $600$ lines per millimetre. The angle $\theta_m$ to several maxima is measured from the central maximum.