engineering physics MCQ #560

The wavelength of the Kα line of an element with atomic number Z is given by

engineering physics MCQ #560

  1. Question 1

    Q1. The wavelength of the Kα line of an element with atomic number Z is given by

    • A) 1 / λ = R * (Z - 1)² * (1/1² - 1/2²)
    • B) 1 / λ = R * (Z - 1) * (1/1² - 1/2²)
    • C) 1 / λ = R * Z² * (1/1² - 1/2²)
    • D) 1 / λ = R * (Z + 1)² * (1/1² - 1/2²)

    Answer: 1 / λ = R * (Z - 1)² * (1/1² - 1/2²)

    Explanation: The Kα line corresponds to the transition from n = 2 to n = 1, and its wavelength is given by the Moseley's law, 1 / λ = R * (Z - 1)² * (1/1² - 1/2²).