DP Physics (last assessment 2024)
Question 18M.2.SL.TZ2.4b.ii
| Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.2.SL.TZ2.4b.ii |
| Level | SL | Paper | 2 | Time zone | TZ2 |
| Command term | Determine | Question number | b.ii | Adapted from | N/A |
b.ii.
[Maximum mark: 2]
18M.2.SL.TZ2.4b.ii
The diagram shows a potential divider circuit used to measure the emf E of a cell X. Both cells have negligible internal resistance.
AB is a wire of uniform cross-section and length 1.0 m. The resistance of wire AB is 80 Ω. When the length of AC is 0.35 m the current in cell X is zero.
(b.ii)
Determine E.
[2]
Markscheme
current leaving 12 V cell is = 0.15 «A»
OR
E = × 28
E = «0.15 × 28 =» 4.2 «V»
Award [2] for a bald correct answer
Allow a 1sf answer of 4 if it comes from a calculation.
Do not allow a bald answer of 4 «V»
Allow ECF from incorrect current
[2 marks]