Assertion: As work function of a material increases by some mechanism, it requires greater energy to excite the electrons from its surface. Reason: A plot of stopping potential (Vs) versus frequency ( upsilon) for different metals, has greater slope for metals with greater work functions.

Question

Assertion: As work function of a material increases by some mechanism, it requires greater energy to excite the electrons from its surface. Reason: A plot of stopping potential (Vs) versus frequency ( upsilon) for different metals, has greater slope for metals with greater work functions. (A) If both assertion and reason are true and reason is the correct explanation of assertion (B) If both assertion and reason are true but reason is not the correct explanation of assertion (C) If assertion is true but reason is false (D) If both assertion and reason are false

Tardigrade Admin · Accepted Answer

As eVs=h upsilon-W Vs=((h/e)) upsilon-((W/e)) For Vs versus upsilon graph, slope = (h/e) = constant.

Q. Assertion : As work function of a material increases by some mechanism, it requires greater energy to excite the electrons from its surface.
Reason : A plot of stopping potential (V_s) versus frequency ( $υ$ ) for different metals, has greater slope for metals with greater work functions.

If both assertion and reason are true and reason is the correct explanation of assertion

If both assertion and reason are true but reason is not the correct explanation of assertion

If assertion is true but reason is false

If both assertion and reason are false

As $e V_{s} = h υ - W$
$V_{s} = (\frac{h}{e}) υ - (\frac{W}{e})$
For $V_{s}$ versus \upsilon graph, slope = $\frac{h}{e}$ = constant.

Q. Assertion : As work function of a material increases by some mechanism, it requires greater energy to excite the electrons from its surface. Reason : A plot of stopping potential (Vs) versus frequency (υ) for different metals, has greater slope for metals with greater work functions.