Question: Q. 1. Name the type of EM waves having a wavelength range of $0.1 \mathrm{~m}$ to $1 \mathrm{~mm}$. How are these waves generated ? Write their two uses.
U [O.D. comptt II 2018
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Solution:
Ans. Name of EM wave
Method of generation
Two uses
Microwaves
Produced by special vacuum tubes
Klyston, magnetron, gunn diodes
Uses :
(i) In Radar system for aircraftnavigation
(ii) In ovens for heating/cooking
$1 / 2+1 / 2$
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Detailed Answer :
(i) Microwaves: Wavelength $10^{-4} \mathrm{~m}-10^{-1} \mathrm{~m}$, frequency $10^{13} \mathrm{~Hz}-10^{9} \mathrm{~Hz}$
(ii) Generation :
Microwaves are produced by valves like magnetron or using a maser. They are detected with crystal detectors or solid-state diodes.
(iii) Uses :
(a) Used in radar
(b) Used in telemetry
OR
(a) Used in electron spin resonance studies
(b) Used in microwave ovens for heating food
$1 / 2$
