Question 19M.1B.SL.TZ2.b
| Date | May 2019 | Marks available | [Maximum mark: 3] | Reference code | 19M.1B.SL.TZ2.b |
| Level | SL | Paper | 1B | Time zone | TZ2 |
| Command term | Determine | Question number | b | Adapted from | N/A |
Determine, using the graph, the emf of the cell including the uncertainty for this value. Give your answer to the correct number of significant figures.
[3]
evidence that ε can be determined from the y-intercept of the line of best-fit or lines of min and max gradient ✔
states ε=1.59 OR 1.60 OR 1.61V«» ✔
states uncertainty in ε is 0.02 V«» OR 0.03«V» ✔
The number of candidates who realised that the V intercept was EMF was disappointing. Large numbers of candidates tried to calculate ε using points on the graph, often ending up with unrealistic values. Another common mistake was not giving values of ε and Δε to the correct number of digits - 2 decimal places on this occasion. Very few candidates drew maximum and minimum gradient lines as a way of determining Δε.
