Calculate the energy in joule corresponding to light of wavelength 45 nm (Planck's constant, h=6.63×10-34 Js; speed of light, c=3× 108 ms-1).

Question

Calculate the energy in joule corresponding to light of wavelength 45 nm (Planck's constant, h=6.63×10-34 Js; speed of light, c=3× 108 ms-1). (A) 6.67×1015 (B) 6.67×1011 (C) 6.63×10-15 (D) 4.42×10-18

Tardigrade Admin · Accepted Answer

The wavelength of light is related to its energy by the equation,

E = \frac{h c}{λ}, (E = h v)

Given,

λ = 45 nm = 45 \times 1 0^{- 9} m [∵ 1 nm = 1 0^{- 9} m]

Hence,

E = \frac{6.63 \times 1 0 ^{- 34} J s \times 3 \times 1 0 ^{8} m s ^{- 1}}{45 \times 1 0 ^{- 9} m}

= 4.42 \times 1 0^{- 18} J

Hence, the energy corresponds to light of wavelength

45 nm

is

4.42 \times 1 0^{- 18} J

.

Q. Calculate the energy in joule corresponding to light of wavelength $45 nm$ (Planck's constant, $h = 6.63 \times 1 0^{- 34} J s$ ; speed of light, $c = 3 \times 1 0^{8} m s^{- 1}$ ).

$6.67 \times 1 0^{15}$

$6.67 \times 1 0^{11}$

$6.63 \times 1 0^{- 15}$

$4.42 \times 1 0^{- 18}$

Q. Calculate the energy in joule corresponding to light of wavelength 45nm (Planck's constant, h=6.63×10−34Js; speed of light, c=3×108ms−1).

6.67×1015

6.67×1011

6.63×10−15

4.42×10−18

The wavelength of light is related to its energy by the equation, E=λhc​,(E=hv) Given, λ=45nm=45×10−9m[∵1nm=10−9m] Hence, E=45×10−9m6.63×10−34Js×3×108ms−1​ =4.42×10−18J Hence, the energy corresponds to light of wavelength 45nm is 4.42×10−18J.

Q. Calculate the energy in joule corresponding to light of wavelength $45 nm$ (Planck's constant, $h = 6.63 \times 1 0^{- 34} J s$ ; speed of light, $c = 3 \times 1 0^{8} m s^{- 1}$ ).

$6.67 \times 1 0^{15}$

$6.67 \times 1 0^{11}$

$6.63 \times 1 0^{- 15}$

$4.42 \times 1 0^{- 18}$