Work function of a metal is 5.26 × 10-18 then its threshold wavelength will be :

Question

Work function of a metal is 5.26 × 10-18 then its threshold wavelength will be : (A)  736.7 mathringA (B)  760.7 mathringA  (C)  301 mathringA (D)  344.4 mathringA

Tardigrade Admin · Accepted Answer

Work function W=(h c/λ) λ =(h c/W) =(6.6 × 10-34 × 3 × 108/5.26 × 10-18)=344.4 mathringA

Q. Work function of a metal is $5.26 \times 1 0^{- 18}$ then its threshold wavelength will be :

$736.7 \overset{˚}{A}$

$760.7 \overset{˚}{A}$

$301 \overset{˚}{A}$

$344.4 \overset{˚}{A}$

Work function $W = \frac{h c}{λ}$
$λ = \frac{h c}{W}$
$= \frac{6.6 \times 1 0 ^{- 34} \times 3 \times 1 0 ^{8}}{5.26 \times 1 0 ^{- 18}} = 344.4 \overset{˚}{A}$

Q. Work function of a metal is 5.26×10−18 then its threshold wavelength will be :

736.7A˚

760.7A˚

301A˚

344.4A˚