If I is intensity and f is the frequency of radiation incident on a photo sensit | TestHub

PhysicsMediummultiple choice

If I is intensity and f is the frequency of radiation incident on a photo sensitive metal in the photo-electric experiment set up :

Answer:

B, D

Solution:

Photon flux $N = \frac{I}{h f}; i_{s a t} \propto N$ .

(A) f increased at constant I ⇒ N decreases ⇒ saturation current decreases ⇒ INCORRECT

(B) f decreased (above threshold) at constant I ⇒ N increases ⇒ saturation current increases ⇒ CORRECT

(C) KE just after ejection depends only on f and work-function, not on cathode-anode distance ⇒ INCORRECT

(D) Lower work-function, same f and I ⇒ same photon flux ⇒ saturation current same ⇒ CORRECT

Hence (B), (D).

Stream:JEESubject:PhysicsTopic:Modern PhysicsSubtopic:Photoelectric effect

⏱ 2mℹ️ Source: QB

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