Waves

Waves keywords

Reflection

Amplitude and wavelength

Ultrasound

Electromagnetic Spectrum help 

Seismic Waves - Multi Choice

Foundation Physics Book
You need the text book to do these questions

Revision resources

some web resources

Characteristics of waves Revision Q/A

EM spectrum and sound Revision Q/A

The syllabus

some more revision questions -  I know they look small - they will print out at a decent size

Waves OCR syllabus

 describe the effects of absorbing electromagnetic waves: heating, ionisation and damage to cells and tissue.

 explain that wave motion involves an oscillation.

 describe the differences between a transverse and a longitudinal wave and give one example of each.

 recall the meaning of frequency, wavelength and amplitude.  

 identify the wavelength and amplitude of a transverse wave.

 describe the effect on the loudness of a sound when the amplitude is changed.  

 describe the effect on the pitch of a sound when the frequency is changed.

 state and be able to use the equation wave speed = frequency x wavelength.  speed (m/s) = f (hertz) x wavelength (m)

 describe how echoes are caused by the reflection of sound.

 recall that refraction involves the change in speed of a wave.

 explain how changing the speed of a wave causes a change in wavelength and this may cause a change in direction.

 explain and illustrate how virtual images are caused by the refraction of light.

 recall that waves can be reflected at a plane barrier and that the angle of incidence equals the angle of reflection.

 explain and illustrate how plane waves are reflected at a concave barrier, and how circular ripples are reflected at a plane barrier.

 recall that water waves can be refracted if they are slowed down.

 recall that water waves can spread out at a narrow gap and that this is known as diffraction.

 describe how the amount of spreading depends on the size of the gap compared to the wavelength of the wave.

 recall that light can be diffracted but needs a very small gap as the wavelength of light is very small.

 appreciate that the diffraction of light is evidence for the wave nature of light.

 explain that sound can be diffracted.

 describe how the amount of diffraction of sound depends on the size of the sound source and the wavelength of the sound. . 

The Electromagnetic Spectrum

 recall that the different types of electromagnetic waves form a continuous spectrum with a range of wavelength and frequency and that they transfer energy at the same speed in free space.

 list the parts of the spectrum in order of wavelength and frequency (gamma rays; X-rays; ultraviolet; light; infra-red; microwaves; radio waves).

 recall that microwaves cause heating when absorbed by water and cause burns when absorbed by body tissue.

 recall that infra-red radiation causes heating when absorbed by any object, and its use in radiant heaters.

 recall that ultra-violet radiation is produced in fluorescent lights.

 recall that being out in the Sun for too long can cause sunburn and skin cancer from the ultra-violet radiation.

 explain that the darker the skin, the more ultra-violet radiation is absorbed by the skin and the less reaches the deeper body tissues to cause these cells to become cancerous.

 describe how information can be transmitted using electromagnetic radiation, including the use of satellites for global communication.

 explain that radio waves are readily diffracted and are therefore suitable for broadcasting.

 explain how information in narrow beams can be transmitted using microwaves.

 describe the use of infra-red radiation in night photography.

 describe what happens to light incident on a perspex/glass-air surface both above and below the critical angle of incidence.

 describe how light is reflected at the inner face of a right-angled prism.

 explain how optical fibres are used in endoscopy.  .

 explain how optical fibres allow the rapid transmission of data using digital signals.

 describe the transmission of data pulses using light in optical fibres.

 describe the difference between analogue and digital signals.

 describe the advantage of using digital signals to allow more information to be transmitted.  H

 explain that X-rays pass through flesh but are absorbed by bone.

 list the safety precautions that should be taken when using X-rays and gamma- rays.,

 interpret given information about the development of ideas concerning the dangers involved with using X-rays and/or radioactive substances.

 describe the use of gamma-rays as tracers to detect malfunction of organs and as treatment for killing body tissue.  

 recall that ultrasound is a high-frequency longitudinal wave.

 explain how distances can be measured using echo-sounding.

 explain how the reflection of ultrasound by body tissue enables organs to be scanned.

 describe how ultrasound is used for pre-natal scanning. IT.

 describe one non-medical use of ultrasound. IT.

Seismic Waves

 recall that earthquakes produce shock waves, which affect the surface of the Earth and travel inside the Earth, and which can be detected by instruments (seismometers) located on the Earth's surface.

 recall that during earthquakes there are several types of wave produced:

  -  P-waves (primary waves) which are longitudinal waves which travel through both solids and liquids and travel faster than S-waves

 S-waves (secondary waves) which are transverse waves which travel through solids but not through liquids.

 explain how the differences in behaviour of P-waves and S-waves inside the Earth can be interpreted in terms of a simple mantle/core structure for the inner Earth.

 explain how the seismographic record can be used to find the speed of seismic waves, which give evidence for the structure of the Earth. . 

 describe the composition of the Earth(tm)s outermost layer in terms of plates in relative motion:

  -  the upper part of the lithosphere is the crust which is thinner under oceans and thicker under continents

  -  the lithosphere is broken into large plates which move because of the massive convection currents which occur below the lithosphere in the deep interior.

 relate plate tectonic processes to the formation, deformation and recycling of rocks:

  -  plates collide at subduction zones where the oceanic lithosphere descends below the continental lithosphere, forming off-shore trenches and parallel mountain chains with volcanoes. This process can cause earthquakes

  -  the forces at the plate boundaries contribute to the rock cycle

  -  sea floor spreading causes fractures (cracks) which are filled with molten material from below the lithosphere, producing new rock

  -  at subduction zones, increased temperature and pressure can cause metamorphism producing new rocks by recrystallisation, without melting

  -  the descending lithosphere enters the hot mantle and partially melts to form magma

  -  rising magma can crystallise deep below the surface to form coarse-grained rocks (e.g. granite) or rise to the surface in volcanoes to form fine-grained rocks (e.g. basalt lava or volcanic ash).

 interpret given information about developments in ideas of plate tectonics. [No recall is expected.]