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

JEE Main Physical Chemistry in other years

Keep practicing Physical Chemistry

Work through every JEE Main Physical Chemistry PYQ, year by year.

Browse all Chemistry topics

JEE Main 2023 — Chemistry Physical Chemistry

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Solution

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JEE Main Physical Chemistry in other years

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JEE Main 2023 — Chemistry Physical Chemistry

Did you get this right?

Solution

Your note

JEE Main Physical Chemistry in other years

More JEE Main Physical Chemistry questions

Other Chemistry topics for JEE Main

Organic Chemistry

Inorganic Chemistry

Keep practicing Physical Chemistry