A photon has wavelength 3 nm, then its momentum and energy respectively will be [h = 6.63 × 10⁻³⁴ Js, c = velocity of light = 3 × 10⁸ m/s] (a) 2.21 × 10⁻⁴³ kg ms⁻¹; 6.63 × 10⁻³⁴ J (b) 2.21 × 10⁻³⁴ kg ms⁻¹; 6.63 × 10⁻²⁵ J (c) 2.21 × 10⁻²⁵ kg ms⁻¹; 6.63 × 10⁻¹⁷ J (d) 2.21 × 10⁻¹⁶ kg ms⁻¹; 6.63 × 10⁻¹⁹ J

Answer: (c). p = (h)/(λ) = 6.63 × 10⁻³⁴3 × 10⁻⁹ = 2.21 × 10⁻²⁵ kg m s⁻¹ E = pc = (2.21 × 10⁻²⁵)(3 × 10⁸) = 6.63 × 10⁻¹⁷ J So the answer is (c).

A photon has wavelength 3 nm, then its momentum and energy… | MHT CET 2021 (24 Sep, Shift 1)

Q22MHT CET 2021 · 24 SEP · SHIFT 1Easy

Photons: Energy, Momentum & Radiation Pressure

A photon has wavelength $3\text{ nm}$ , then its momentum and energy respectively will be $[h = 6.63 \times 10^{-34}\text{ Js}, c =$ velocity of light $= 3 \times 10^{8}\text{ m/s}]$

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Answer: (c)

$p = \frac{h}{\lambda} = \frac{6.63 \times 10^{-34}}{3 \times 10^{-9}} = 2.21 \times 10^{-25}\text{ kg m s}^{-1}$
$E = pc = (2.21 \times 10^{-25})(3 \times 10^{8}) = 6.63 \times 10^{-17}\text{ J}$
So the answer is (c).

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Photons: Energy, Momentum & Radiation Pressure question from MHT CET 2021 (24 Sep, Shift 1)

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