DP Physics (last assessment 2024)

Test builder »

Question 19M.1.HL.TZ1.38

Select a Test
Date May 2019 Marks available [Maximum mark: 1] Reference code 19M.1.HL.TZ1.38
Level HL Paper 1 Time zone TZ1
Command term Question number 38 Adapted from N/A
38.
[Maximum mark: 1]
19M.1.HL.TZ1.38

A metallic surface is first irradiated with infrared radiation and photoelectrons are emitted from the surface. The infrared radiation is replaced by ultraviolet radiation of the same intensity.

What will be the change in the kinetic energy of the photoelectrons and the rate at which they are ejected?

[1]

Markscheme

A

Examiners report

With a low difficulty index, fewer than 15 % of candidates correctly selected response A. The large majority of candidates selected response C. These candidates likely did not recognize that since intensity stays constant, there must be fewer ultraviolet photons ejected for the power per unit area to remain constant. The discrimination index was very low for this question.

Syllabus sections