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Question
Ultraviolet radiation has a wavelength of 300Å. If the velocity of the electromagnetic wave is 3 × 108 ms-1. Calculate:
- frequency
- time period.
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Solution
Wavelength = λ = 300Å = 300 × 10-10 m
Velocity = v = 3 × 108 ms-1
Frequency = f = ?
Time period = T = ?
(i) We know v = λf
f = `"v"/lambda = (3 xx 10^8)/(300 xx 10^-10)`
f = `(3 xx 10^8)/(3 xx 10^-8) = 10^16` Hz
(ii) Time period = T = `1/"f"`
T = `1/10^16`
T = 10-16 s
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