NTA Abhyas JEE Main2020ChemistryStructure of AtomPractice
An electron practically at rest, is initially accelerated through a potential difference of 100 volts. It then has a de Broglie wavelength = λ 1 Å . It then get retorted through 19 volts and then has a wavelength λ 2 Å . It further retardation through 3.2 volts changes the wavelength to λ 3 . What is the value of λ 3 - λ 2 λ 1 ?
Options
- A20 41
- B10 63
- C20 63
- D10 41
Correct answer
C. 20 63
Step-by-step solution
λ = h 2 m e V λ 1 = h 2 m e 100 = h 10 2 m e = k 10 k = h 2 m e λ 2 = h 2 m e 81 = k 9 λ 3 = h 2 m e 49 = k 7 λ 3 - λ 2 λ 1 = k 7 - k 9 k 10 = 2 k 63 k 10 = 20 63