Threshold Frequency — Practice Quiz

Question 1

Work function of a metal is 3.1 eV. Threshold wavelength:

Accepted Answer

400 nm

Answer

300 nm

Answer

500 nm

Answer

600 nm

Question 2

Below threshold frequency, increasing the intensity:

Accepted Answer

Has no effect on emission

Answer

Eventually emits electrons

Answer

Increases K_max

Answer

Decreases the work function

Question 3

If threshold frequency is 6 × 10¹⁴ Hz, work function is:

Accepted Answer

2.48 eV

Answer

1.5 eV

Answer

4 eV

Answer

3 eV

Question 4

Which metal would NOT emit photoelectrons with green light (λ = 550 nm)?

Accepted Answer

Copper (φ = 4.7 eV)

Answer

Cesium (φ = 2.14 eV)

Answer

Sodium (φ = 2.28 eV)

Answer

Potassium (φ = 2.30 eV)

Question 5

Why is threshold frequency a function only of metal, not of light?

Accepted Answer

f₀ depends only on the work function (a metal property)

Answer

Light has no effect

Answer

Different lights have different f₀

Answer

Wave theory says so