PYQ NEET- Dual Nature Of Matter And Radiation L-9

Question: When the energy of the incident radiation is increased nby $20 %$, the kinetic energy of the photoelectrons emitted from a metal surface increased from $0.5 \mathrm{eV}$ to $0.8 \mathrm{eV}$. The work function of the metal is#

A) $0.65 \mathrm{eV}$

B) $1.0 \mathrm{eV}$

C) $1.3 \mathrm{eV}$

D) $1.5 \mathrm{eV}$

Answer: $1.0 \mathrm{eV}$#

Solution:#

$$ \begin{aligned} & 0.5=\mathrm{E}-\phi \ & \Rightarrow 0.8=1.2 \mathrm{E}-\phi \end{aligned} $$

From above expressions, work function $\phi=1 \mathrm{eV}$