Pupil sheet · Light and the electromagnetic spectrum
Light and the electromagnetic spectrum — final check
Name ______________________ Date ____________
Work alone, with the lesson closed. Answer every question; there are no hints.
1. explain / state
(a) Explain why white light is spread into colours by a glass prism, and name the process. (b) Identify the colour of the visible spectrum with the longest wavelength and the colour with the highest frequency. (c) Identify the region of the electromagnetic spectrum just beyond each end of the visible spectrum, and state which of the seven main regions has the lowest frequency. (d) Supplement. A beam of light passes through a prism and is bent, but it is not spread out at all: the card shows one sharp spot. Identify this kind of light and state what is special about it.
(a) Why the prism spreads white light
(b) Longest wavelength; highest frequency
(c) Beyond each end; lowest frequency
(d) Supplement: the light that stays one colour
2. compare / state / explain / describe
(a) Compare the speeds of infrared and ultraviolet in a vacuum. (b) Supplement. A signal travels 6.0 × 108 m through space. How long does it take? (c) Identify the region used for each of these, and explain why one of them suits its job: medical scanning of a broken leg; an electric grill; illumination of a room. (d) Describe the harmful effects of too much infrared and of too much microwave radiation.
(b) Supplement: Time: ______________ unit ________
(a) The speeds, (c) the regions and a reason, and (d) the harmful effects