Photoelectric Effect — Practice Quiz

Question 1

A metal of work function 2 eV is illuminated by light of wavelength 400 nm. Maximum KE of ejected photoelectrons:

Accepted Answer

1.1 eV

Answer

2 eV

Answer

3.1 eV

Answer

0.5 eV

Question 2

Threshold wavelength for a metal with φ = 2.48 eV:

Accepted Answer

500 nm

Answer

400 nm

Answer

620 nm

Answer

300 nm

Question 3

If light intensity is doubled (same frequency), what changes?

Accepted Answer

Saturation current doubles

Answer

K_max doubles

Answer

Threshold frequency halves

Answer

Stopping potential doubles

Question 4

Slope of V_s vs f graph equals:

Accepted Answer

h/e

Answer

h

Answer

φ

Answer

e/h

Question 5

Photoelectric current saturates because:

Accepted Answer

All emitted electrons reach the anode

Answer

Cathode runs out of electrons

Answer

Photons stop arriving

Answer

Work function vanishes

Question 6

If a metal's φ = 4 eV is illuminated by 300 nm light, K_max is:

Accepted Answer

0.13 eV

Answer

0.1 eV

Answer

0.5 eV

Answer

Negative (no emission)