de Broglie Wavelength of Electron in Second Orbit | JEE Mains PYQ | Structure of Atom
Q. If a0 is denoted as the Bohr radius of hydrogen atom, then what is the de-Broglie wavelength (λ) of the electron present in the second orbit of hydrogen atom? [ n : any integer ]

(A) 8πa0 / n

(B) 2a0 / nπ

(C) na0 / 4π

(D) 4πa0 / n

Explanation
Step 1: Bohr’s quantization condition

According to Bohr model:
2πrn = nλ

Step 2: Radius of nth orbit

For hydrogen atom:
rn = n²a0

Step 3: Substitute rn in Bohr condition

2π(n²a0) = nλ
λ = 2πn a0

Step 4: Write in general form

λ = 8πa0 / n

Correct Answer = 8πa0 / n (Option A)

Updated for JEE Main 2026: This PYQ is important for JEE Mains, JEE Advanced and other competitive exams. Practice more questions from this chapter.

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