DP Physics (last assessment 2024)
Question 19M.3.SL.TZ2.a
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.3.SL.TZ2.a |
| Level | SL | Paper | 3 | Time zone | TZ2 |
| Command term | Outline | Question number | a | Adapted from | N/A |
a.
[Maximum mark: 1]
19M.3.SL.TZ2.a
A student investigates the electromotive force (emf) ε and internal resistance r of a cell.
The current I and the terminal potential difference V are measured.
For this circuit V = ε - Ir .
The table shows the data collected by the student. The uncertainties for each measurement
are shown.
The graph shows the data plotted.
The student has plotted error bars for the potential difference. Outline why no error bars are shown for the current.
[1]
Markscheme
ΔI is too small to be shown/seen
OR
Error bar of negligible size compared to error bar in V ✔
Examiners report
Almost all candidates realised that the uncertainty in I was too small to be shown. A common mistake was to mention that since I is the independent variable the uncertainty is negligible.
