In the photoelectric effect, the maximum speed of electrons is found to be 6× 105 m s- 1 . The wavelength used is 4000 Å . The work function of the metal is

Question

In the photoelectric effect, the maximum speed of electrons is found to be 6× 105 m s- 1 . The wavelength used is 4000 Å . The work function of the metal is (A)  text2.2eV (B)  text2.076eV (C)  text2.3eV (D)  text2.4eV

Tardigrade Admin · Accepted Answer

(hc/λ )=(KE)Max+φ (12400/4000)=((1/2) × 9 .1 × 10- 31 × 36 × 1010/1 .6 × 10- 19)+φ text3.1= text102.375× 10- 2+φ φ= text2.076eV

Q. In the photoelectric effect, the maximum speed of electrons is found to be $6 \times 1 0^{5} m s^{- 1}$ . The wavelength used is $4000 Å$ . The work function of the metal is

$2.2 e V$

$2.076 e V$

$2.3 e V$

$2.4 e V$

$\frac{h c}{λ} = (K E)_{M a x} + ϕ$
$\frac{12400}{4000} = \frac{\frac{1}{2} \times 9.1 \times 1 0 ^{- 31} \times 36 \times 1 0 ^{10}}{1.6 \times 1 0 ^{- 19}} + ϕ$
$3.1 = 102.375 \times 1 0^{- 2} + ϕ$
$ϕ = 2.076 e V$

Q. In the photoelectric effect, the maximum speed of electrons is found to be 6×105ms−1 . The wavelength used is 4000Å . The work function of the metal is

2.2eV

2.076eV

2.3eV

2.4eV