JEE Main201910 Jan 2019Morning ShiftPhysicsDual Nature of MatterActual
In an electron microscope, the resolution that can be achieved is of the order of the wavelength of electrons used. To resolve a width of 7.5 × 10 - 12 m , the minimum electron energy required is close to:
Options
- A100 k e V
- B25 k e V
- C1 k e V
- D500 k e V
Correct answer
B. 25 k e V
Step-by-step solution
λ = 150 V ⇒ 7.5 × 10 - 2 = 150 V V = 150 7.5 × 7.5 × 10 - 4 = 80 3 k V V ≈ 25   K e V