A radioactive source emits X–rays of very short wavelength (10 -13m ). what is the frequency of these rays?
-
A.
2 × 1018HZ -
B.
3 × 10 19HZ -
C.
3 × 1021HZ -
D.
3 × 10-19HZ
Correct Answer: Option C
Explanation
(Wavelength (lambda) = 10^{-13}m)
Speed of X-ray = speed of light (C = 3×10^{8}m/s)
Frequently (f) = ?
(Using V = flambda (or (– f π for electromagnetic wave))
(f = frac{c}{lambda} = 3 times 10^{8} ÷ 10^{-13} = 3 times 10^{8} times 10^{13})
= (3 times 10^{8} times 10^{13})
= (3 times 10^{21}Hz)
There is an explanation video available below.