Question

The threshold frequency for a certain photosensitive metal is ${\nu }_0$. When it is illuminated by light of frequency $\nu =2{\nu }_0$, the stopping potential for photoelectric current is$V_0$. What will be the stopping potential when the same metal is illuminated by light of frequency $\nu =3{\nu }_0$?

• A. $1.5V_0$
• B. $2V_0$
• C. $2.5V_0$
• D. $3V_0$

Answer 1

The correct option is B $2V_0$

For light of frequency $2v_0,$ we have $2h{\nu }_0=h{\nu }_0+e{V}_0\Rightarrow h{\nu }_0=e{V}_0$ .....(i)
For light of frequency $3v_0$, we have $3h{\nu }_0=h{\nu }_0+eV\Rightarrow 2h{V}_0=eV$ .....(ii)
From (i) and (ii), we get $V=2V_0$
Hence, the correct choice is (b).