Structure Of Atom Ques 64

64. If the energy of a photon is given as $3.03 \times 10^{-19} $ $J$ then, the wavelength $(\lambda)$ of the photon is :

[2000]

(a) $6.56 $ $nm$

(b) $65.6 $ $nm $

(c) $656 $ $nm$

(d) $0.656 $ $nm$

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Answer:

Correct Answer: 64.(c)

Solution:

  1. (c) The energy of photon,

$E=\frac{h c}{\lambda}=3.03 \times 10^{-19}$

or $\lambda=\frac{6.626 \times 10^{-34} \times 3 \times 10^{8}}{3.03 \times 10^{-19}}$

or $\lambda=\frac{19.878}{3.03} \times 10^{-7}=6.56 \times 10^{-7} m=656$ $ nm$