Dual Nature Of Light Question 489
Question: The wavelength of most energetic X-rays emitted when a metal target is bombarded by 40KeV electrons, is approximately ( $ h=6.62\times {{10}^{-34}} $ J-sec; 1 eV = $ 1.6\times {{10}^{-19}} $ J; c = $ 3\times 10^{8},m/s) $ [MNR 1991; MP PMT 1999; UPSEAT 2000; Pb. PET 2004]
Options:
A) 300 Å
B) 10 Å
C) 4 Å
D) 0.31 Å
Show Answer
Answer:
Correct Answer: D
Solution:
$ \lambda ,=\frac{12375}{(40\times 10^{3})}=0.309{\AA}\approx 0.31{\AA} $
BETA
