engineering physics MCQ #472

The wavelength of the radiation emitted when an electron jumps from n = 4 to n = 1 is given by 1 / λ = R (1 / 1² - 1 / 4²).

engineering physics MCQ #472

  1. Question 1

    Q1. The wavelength of the radiation emitted when an electron jumps from n = 4 to n = 1 is given by 1 / λ = R (1 / 1² - 1 / 4²).

    • A) 972 Å
    • B) 1026 Å
    • C) 1216 Å
    • D) 6563 Å

    Answer: 972 Å

    Explanation: Substitute n1 = 1, n2 = 4, and R = 1.097 × 10⁷ m⁻¹ to get 1 / λ = 1.097 × 10⁷ (1 - 1/16) = 1.028 × 10⁷, λ = 972 Å.