engineering physics MCQ #451

The wavelength of the first line of Balmer series is given by 1 / λ = R * (1 / 2² - 1 / 3²). The value of λ is

engineering physics MCQ #451

  1. Question 1

    Q1. The wavelength of the first line of Balmer series is given by 1 / λ = R * (1 / 2² - 1 / 3²). The value of λ is

    • A) 656 nm
    • B) 486 nm
    • C) 434 nm
    • D) 410 nm

    Answer: 656 nm

    Explanation: 1 / λ = R * (1/4 - 1/9) = 5R/36, so λ = 36 / (5R) = 36 / (5 * 1.097 * 10^7) = 656 nm.