Question

The graph of stopping potential `"V"_"s"` against frequency v of incident radiation is plotted for two different metals P and Q as shown in the graph. Φ_P and Φ_Q are work-functions of P and Q respectively, then

Options

• Φ_P > Φ_Q 

• Φ_P < Φ_Q 

• Φ_P = Φ_Q 

• v₀ < v₀ 

Answer 1

Φ_P < Φ_Q 

Explanation:

The work-function of a surface is

Φ = hv₀ 

where, h = Planck's constant

and v₀ = threshold frequency.

From graph it is clear that,

`("v"_0)_"P" < ("v"_0)_"Q"`

∴ Φ_P < Φ_Q