Cambridge IGCSE Physics3.3 The electromagnetic spectrum Checklist

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What's on this checklist

Core

I know the main regions of the electromagnetic spectrum, in order of frequency and in order of wavelength.
I know that all electromagnetic waves travel at the same high speed in a vacuum.
I can describe typical uses of the different regions of the electromagnetic spectrum, including:a)radio waves: radio and television transmissions, astronomy, radio frequency identification (RFID)b)microwaves: satellite television, mobile phones (cell phones), microwave ovensc)infrared: electric grills, short-range communications such as remote controllers for televisions, intruder alarms, thermal imaging, optical fibresd)visible light: vision, photography, illuminatione)ultraviolet: security marking, detecting fake bank notes, sterilising waterf)X-rays: medical scanning, security scannersg)gamma rays: sterilising food and medical equipment, the detection of cancer and its treatment
I can describe the harmful effects on people of too much exposure to electromagnetic radiation, including:a)microwaves: internal heating of body cellsb)infrared: skin burnsc)ultraviolet: damage to surface cells and eyes, leading to skin cancer and eye conditionsd)X-rays and gamma rays: mutation of, or damage to, cells in the body
I know that communication with artificial satellites is mainly by microwaves:a)some satellite phones use artificial satellites in low orbitb)some satellite phones, and direct broadcast satellite television, use geostationary satellites

I know that the speed of electromagnetic waves in a vacuum is 3.0 × 10⁸ m/s, and that it is approximately the same in air.
I know that many important communication systems rely on electromagnetic radiation, including:a)mobile phones (cell phones) and wireless internet, which use microwaves because microwaves can penetrate some walls and need only a short aerial to transmit and receiveb)Bluetooth, which uses radio waves because radio waves pass through walls, although the signal is weakened when they doc)optical fibres (visible light or infrared), used for cable television and high-speed broadband because glass is transparent to visible light and some infrared, and visible light and short-wavelength infrared can carry high rates of data
I know the difference between a digital signal and an analogue signal.
I know that a sound can be transmitted as a digital signal or as an analogue signal.
I can explain the benefits of digital signalling, including a higher rate of data transmission and a greater range because the signal can be regenerated accurately.