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Dual Nature of Radiation and Matter — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsDual Nature of Radiation and Matter2 Marks
Question
If work function of caesium metal is $2.14 eV$ , then calculate its threshold frequency.
✓

Answer

Work function
$\phi=h v_0$
$2.14 \times 1.6 \times 10^{-19}=6.63 \times 10^{-34} v_0$
$v_0=\frac{2.14 \times 1.6 \times 10^{-19}}{6.63 \times 10^{-34}}$
$=0.516 \times 10^{15}$
$=5.16 \times 10^{14} Hz$

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