Question

Above graph shows stopping potential versus $rac { 1 } { \text { wavelength } }$ for three metals, then –

• A. Planck's constant for metal (1) is greatest
• B. Work function for metal (3) is greatest
• C. Threshold frequency for metal (1) is greatest
• D. Threshold wavelength is maximum for metal (3)

Answer 1

Answer: (B)

Work function for metal (3) is greatest

Answer 2

eV_S = K.E_max = hν – W

$\mathrm { V } _ { \mathrm { s } } = \frac { \mathrm { hc } } { \mathrm { e } \lambda } - \frac { \mathrm { W } } { \mathrm { e } }$ [W = work function]