Photoelectric effect experiments are performed using three different metal plates p , q and r having work functions φ p =2.0 eV , φ q =2.5 eV and φ t =3.0 eV, respectively. A light beam containing wavelengths of 550 nm , 450 nm and 350 nm with equal intensities illuminates each of the plates. The correct I - V graph for the experiment is (Take h c=1240 eV nm )

Question

Photoelectric effect experiments are performed using three different metal plates p , q and r having work functions φ p =2.0 eV , φ q =2.5 eV and φ t =3.0 eV, respectively. A light beam containing wavelengths of 550 nm , 450 nm and 350 nm with equal intensities illuminates each of the plates. The correct I - V graph for the experiment is (Take h c=1240 eV nm ) (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

V B =(1 / e )[( hc / λ)-φ] V P =(1 / e )[(1240 / 550)-2] eV =0.2545 V V q =(1 / e )[(1240 / 450)-2.5] eV =0.255 V V r =(1 / e )[(1240 / 350)-3] eV =0.5428 V If n is the number of photons in unit time then nh c / λ = I ⇒ i p: i q: i r = n P: n q: n r =λ p: λ q: λ r

VB​=(1/e)[(hc/λ)−ϕ] VP​=(1/e)[(1240/550)−2]eV=0.2545V Vq​=(1/e)[(1240/450)−2.5]eV=0.255V Vr​=(1/e)[(1240/350)−3]eV=0.5428V If n is the number of photons in unit time then nhc/λ=I ⇒ip​:iq​:ir​=nP​:nq​:nr​=λp​:λq​:λr​