NEET-XII-Physics
qstns with ansrs year:2022
- #7When two monochromatic lights of frequency, `` v `` and `` \frac{v}{2} `` are incident on a photoelectric metal, their stopping potential becomes `` \frac{V_{S}}{2} `` and `` V_{S} `` respectively. The threshold frequency for this metal is :
(A) `` \frac{3}{2} v ``
(B) `` 2 v ``
(C) `` 3 v ``
(D) `` \frac{2}{3} v ``digAnsr: AAns : Using the equation
`` eV - hv -\phi ``
or `` eV = hv - hv _{ Th } ``
`` \frac{ eV _{ s }}{2}=\frac{ hv }{2}- hv _{ Th } ..... `` (1)
`` e V _{ s }= hv - hv _{ Th }...... `` (2)
Data Incorrect