Gamma rays are used The largest angle of to sterilise equipment, (b) incidence at which diagnose blood flow refraction of light will occur problems and treat at a glass/air interface is cancer. 41°. Infrared radiation is used to treat muscle (a) Z (a) Radio waves diffract injuries and in Z more easily because thermograms. X they have a long Ultraviolet radiation is Y wavelength. used to treat skin Reception will likely be diseases, such as Draw around the Perspex poor. Wavelength is psoriasis. block. higher than even TV Shine a ray of light through waves so diffraction is (a) Radio waves are used it and change the angle of less likely. in radio and TV incidence until the angle of communications. refraction is 90°. Surface wave. Microwaves are used Mark the incident ray on It diffracts along the by mobile phones. the paper. surface of the Earth so Measure the angle of must have a long (a) Infrared radiation is incidence with the wavelength. used by remote protractor. controls and heaters. Microwaves are used to heat food. Gamma rays don’t diffract easily and are dangerous to humans. 1.09 ms Refraction (p12 – 13) (a) 3.08 m Refraction is the change in 2.2 ms speed / wavelength / direction of light as it 1.44 x 1011 m moves from one medium to another. Visible light. Diffraction does not involve waves changing Diffraction (p11) medium. Diffraction is the bending of waves around an (Shorter focal length) obstacle. The focal length is the distance (a) between a lens and a screen where a sharp image of a far away object can be seen.
Gamma rays are used to sterilise equipment, diagnose blood flow problems and treat cancer. Infrared radiation is used to treat muscle injuries and in thermograms. Ultraviolet radiation is used to treat skin diseases, such as psoriasis. (a) Radio waves are used in radio and TV communications. Microwaves are used by mobile phones. (a) Infrared radiation is used by remote controls and heaters. Microwaves are used to heat food. Gamma rays don’t diffract easily and are dangerous to humans. 1.09 ms (a) 3.08 m 2.2 ms 1.44 x 1011 m Visible light. Diffraction (p11) Diffraction is the bending of waves around an obstacle. (a) (b) (a) Radio waves diffract more easily because they have a long wavelength. Reception will likely be poor. Wavelength is higher than even TV waves so diffraction is less likely. Surface wave. It diffracts along the surface of the Earth so must have a long wavelength. Refraction (p12 – 13) Refraction is the change in speed / wavelength / direction of light as it moves from one medium to another. Diffraction does not involve waves changing medium. The largest angle of incidence at which refraction of light will occur at a glass/air interface is 41°. (a) Z Z X Y Draw around the Perspex block. Shine a ray of light through it and change the angle of incidence until the angle of refraction is 90°. Mark the incident ray on the paper. Measure the angle of incidence with the protractor. (Shorter focal length) The focal length is the distance between a lens and a screen where a sharp image of a far away object can be seen.
Waves-and-Radiation-Problem-Booklet-27he174.docx