Question

GOOD MORNING
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ANSWER ....
IF WORK FUNCTION IS 4.14 eV , THE THRESHOLD FREQUENCY OF INCIDENT LIGHT IS ?

Answer 1

We know that Work-function of a Given Metal is the Product of Threshold Frequency of the incident light and Plank's constant.

⇒ Work Function = h × ν₀ (where Plank's constant = 6.625 × 10⁻³⁴ J-sec and ν₀ is the Threshold frequency of the incident light)

Given the Work function = 4.14 eV

As Plank's constant is in Joule-sec we need to convert the Work function into Joules

We know that 1eV = 1.6 × 10⁻¹⁹ Joules

⇒ Work Function = 4.14 × 1.6 × 10⁻¹⁹ Joules

⇒ Work Function = 6.624 × 10⁻¹⁹ Joules

Substituting the respective values in the Work function equation we get :

⇒  6.624 × 10⁻¹⁹  = 6.625 × 10⁻³⁴ × ν₀

⇒  ν₀ = 10¹⁵ sec⁻¹

⇒ The Threshold Frequency of the incident light is 10¹⁵ sec⁻¹