(a) How are electromagnetic waves produced? (b) Write the wavelength range and one use of: (i) Microwaves, and (ii) Ultraviolet waves.

Electromagnetic waves are produced by an oscillating (accelerated) charge: it sets up oscillating electric and magnetic fields which regenerate each other and propagate through space as an EM wave.

Microwaves — wavelength range ~$\displaystyle 0.1$ m to $\displaystyle 1$ mm; use: RADAR / microwave ovens.

Ultraviolet waves — wavelength range ~$\displaystyle 4$×$\displaystyle 10$⁻⁷ m ($\displaystyle 400$ nm) to ~$\displaystyle 6$×$\displaystyle 10$⁻¹⁰ m; use: sterilisation of water / LASIK eye surgery / detecting forged bank notes.