The wavelength of an electron… - JEE Main 2023 Chemistry PYQ

JEE Main 2023 — Chemistry Physical Chemistry

2023integermedium

The wavelength of an electron of kinetic energy $4.50\times {10}^{-29}J$ is $________\times 10–5m.$ (Nearest integer) Given: mass of electron is $9\times 10–31\mathrm{kg},h=6.6\times 10–34\mathrm{Js}$

Official previous-year question

Held on 6 Apr 2023 · Verified 6 Jul 2026.

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Solution

Given:

Kinetic energy(K.E.)= $4.55\times {10}^{-29}J$

Mass of electron $({m}_{e})=9.1\times {10}^{-31}\mathrm{kg} h=6.6\times {10}^{-34}J-\mathrm{sec}$

debroglie wavelength ${\lambda }_{d}=\frac{h}{\mathrm{mv}}=\frac{h}{\sqrt{2\mathrm{mKE}}}$

Here $\lambda$ is the de Broglie wavelength, $h$ is Planck's constant, $m$ is the mass of the particle, $v$ is its velocity, and $p$ is the momentum of the particle, which is equal to $\mathrm{mv}$ .

$\lambda =\frac{h}{\sqrt{2\mathrm{mKE}}}$

$=\frac{6.6\times {10}^{-34}}{\sqrt{2\times 9\times {10}^{-31}\times 4.5\times {10}^{-29}}}$ $=\frac{6.6\times {10}^{-34}}{9\times {10}^{-30}}=\frac{6.6}{9}\times {10}^{-4}$

$=\frac{66}{9}\times {10}^{-5}$

$=7.33\times {10}^{-5}$

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JEE Main 2023 — Chemistry Physical Chemistry

2023integermedium

Official previous-year question

Held on 6 Apr 2023 · Verified 6 Jul 2026.

Did you get this right?

Solution

Given:

Kinetic energy(K.E.)= $4.55\times {10}^{-29}J$

Mass of electron $({m}_{e})=9.1\times {10}^{-31}\mathrm{kg} h=6.6\times {10}^{-34}J-\mathrm{sec}$

debroglie wavelength ${\lambda }_{d}=\frac{h}{\mathrm{mv}}=\frac{h}{\sqrt{2\mathrm{mKE}}}$

Here $\lambda$ is the de Broglie wavelength, $h$ is Planck's constant, $m$ is the mass of the particle, $v$ is its velocity, and $p$ is the momentum of the particle, which is equal to $\mathrm{mv}$ .

$\lambda =\frac{h}{\sqrt{2\mathrm{mKE}}}$

$=\frac{6.6\times {10}^{-34}}{\sqrt{2\times 9\times {10}^{-31}\times 4.5\times {10}^{-29}}}$ $=\frac{6.6\times {10}^{-34}}{9\times {10}^{-30}}=\frac{6.6}{9}\times {10}^{-4}$

$=\frac{66}{9}\times {10}^{-5}$

$=7.33\times {10}^{-5}$

Your note

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Solution

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Other Chemistry topics for JEE Main

Organic Chemistry

Inorganic Chemistry

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