The work function for metals A, B and C are respectively 1.92 eV,… - Vidyadip

MCQ

The work function for metals $A, B$ and $C$ are respectively $1.92 \mathrm{eV}$, $2.0 \mathrm{eV}$ and $5 \mathrm{eV}$. According to Einstein's equation, the metals which will emit photo electrons for a radiation of wavelength $4100 \mathring A$ is/are

A
None of these
B
$A$ only
✓
$A$ and $B$ only
D
All the three metals

✓

Answer

Correct option: C.

$A$ and $B$ only

Energy of incident radiations (in eV) $=\frac{12375}{4100}=3.01 \mathrm{eV}$
Work function of metal $A$ and $B$ are less then $3.01 \mathrm{eV}$,
so $A$ and $B$ will emit photo electrons.

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