Question

Answer the following
(a) Name the em waves which are used for the treatment of certain forms of cancer. Write their frequency range.
(b) Welders wear special glass goggles while working. Why? Explain
(c) Why are infrared waves often called as heat waves? Give their one application.

Answer 1

(a) Gamma rays are used for the treatment of certain forms of cancer. The frequency range is $3\times {10}^{19}Hz$ to $5\times {10}^{24}Hz$.
(b) Welders wear special glass googles while working so that they can protect their eyes from harmful electromagnetic(UV) radiation.
(c) Infrared waves are often called as heat waves because they induced resonance in molecules and increase internal energy in a substance.
Infrared waves are used in burglar alarms, security lights and remote controls for television and DVD players.