DP Physics (last assessment 2024)
Question 17N.3.HL.TZ0.16b
Date | November 2017 | Marks available | [Maximum mark: 2] | Reference code | 17N.3.HL.TZ0.16b |
Level | HL | Paper | 3 | Time zone | TZ0 |
Command term | Estimate | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 2]
17N.3.HL.TZ0.16b
An X-ray beam of intensity I0 is incident on lead. After travelling a distance x through the lead the intensity of the beam is reduced to I.
The graph shows the variation of ln with x.
(b)
A technician operates an X-ray machine that takes 100 images each day. Estimate the width of the lead screen that is required so that the total exposure of the technician in 250 working days is equal to the exposure that the technician would receive from one X-ray exposure without the lead screen.
[2]
Markscheme
I =
«ln 25000 = μx» x = 0.17 «cm» or 1.7 «mm»
