The de Broglie wavelength is λ=mvh. For an ideal gas, vrms=m3kT
Therefore: λ=3mkTh
Substituting values: λ=3×5.31×10−26×1.38×10−23×3006.63×10−34
λ=6.62×10−466.63×10−34=2.57×10−236.63×10−34
λ=2.58×10−11 m =25.8×10−12 m, so x≈26
The de Broglie wavelength of an oxygen molecule at 27° C is x × 10^-12 ~m. The value of x is (take Planck's constant =6.63 × 10^-34 ~J. s, Boltzmann…
JEE Main 2026 — Physics Modern Physics
2026mcqmedium
The de Broglie wavelength of an oxygen molecule at 27∘C is x×10−12 m. The value of x is (take Planck's constant =6.63×10−34 J.s, Boltzmann constant =1.38×10−23 J/K, mass of oxygen molecule =5.31×10−26 kg)
Official previous-year question
Held on 23 Jan 2026 · Verified 6 Jul 2026.
Options
- A
24
- B
26
- C
30
- D
20
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