NTA Abhyas JEE Main2020PhysicsDual Nature of MatterPractice
The electric field associated with a light wave is given by E = E 0 sin 1.57 × 10 7 x - c t (where x and t are in metre and second respectively). The stopping potential when this light is used in an experiment on photoelectric effect with the emitter having work function ϕ = 1.9 e V is.
Options
- A0.6 e V
- B1.2 e V
- C1.8 e V
- D2.4 e V
Correct answer
B. 1.2 e V
Step-by-step solution
Given, E = E 0 sin 1.57 × 10 7 x - c t ...(i) ∴ E = E 0 sin ω c x - c t ...(ii) On comparing Equations (i) and (ii), we get ω c = 1.57 × 10 7 = π 2 × 10 7 λ = 4 × 10 - 7 m = 400 n m As, ϕ 0 = h c λ - E K 1.9 = 1242 400 - E K E K = 3.1 - 1.9 e V = 1.2 e V