The wavelength of light in the visible region is about 760 nm for red colour. The energy of photon in eV at the red end of the visible spectrum is

Question

The wavelength of light in the visible region is about 760 nm for red colour. The energy of photon in eV at the red end of the visible spectrum is (A) 6.63 (B) 3.62 (C) 7.61 (D) 1.64

Tardigrade Admin · Accepted Answer

For red light, λ=760 nm Energy, E=h v=(h c/λ) Hence E=(6.63 × 10-34 × 3 × 108/760 × 10-9) =2.62 × 10-19 J =(2.62 × 10-19/1.6 × 10-19) eV =1.64 eV

Q. The wavelength of light in the visible region is about $760 nm$ for red colour. The energy of photon in $e V$ at the red end of the visible spectrum is

$6.63$

$3.62$

$7.61$

$1.64$

For red light, $λ = 760 nm$
Energy, $E = h v = \frac{h c}{λ}$
Hence $E = \frac{6.63 \times 1 0 ^{- 34} \times 3 \times 1 0 ^{8}}{760 \times 1 0 ^{- 9}}$
$= 2.62 \times 1 0^{- 19} J$
$= \frac{2.62 \times 1 0 ^{- 19}}{1.6 \times 1 0 ^{- 19}} e V = 1.64 e V$

Q. The wavelength of light in the visible region is about 760nm for red colour. The energy of photon in eV at the red end of the visible spectrum is

6.63

3.62

7.61

1.64