MCQ
The work function of a metal is $4.2 \mathrm{eV}$, its threshold wavelength will be
- A$4000 \mathring A$
- B$3500 \mathring A$
- ✓$2955 \mathring A$
- D$2500 \mathring A$
✓
Answer
Correct option: C.
$2955 \mathring A$
$W_0(\mathrm{eV})=\frac{12375}{\lambda_0} \Rightarrow \lambda_0=\frac{12375}{4.2} \approx 2955 \mathring A$
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