Question 20N.2.SL.TZ0.c(ii)
| Date | November 2020 | Marks available | [Maximum mark: 3] | Reference code | 20N.2.SL.TZ0.c(ii) |
| Level | SL | Paper | 2 | Time zone | TZ0 |
| Command term | Explain | Question number | c(ii) | Adapted from | N/A |
Slider S of the potential divider is positioned so that the ammeter reads . Explain, without further calculation, any difference in the power transferred by the potential divider arrangement over the arrangement in (b).
[3]
ALTERNATIVE 1
current from the cell is greater «than » ✓
because some of the current must flow through section SQ of the potentiometer ✓
overall power greater «than in part (b)» ✓
ALTERNATIVE 2
total/overall resistance decreases ✓
because SQ and X are in parallel ✓
overall power greater «than in part (b)» ✓
Allow the reverse argument.
HL only. This question challenged candidate's ability to describe clearly the changes in an electrical circuit. It revealed many misconceptions about the nature of electrical current and potential difference, of those who did have a grasp of what was going on the explanations often missed the second point in each of the markscheme alternatives as detail was missed about where the current was flowing or what was in parallel with what.
