Higher November 2022 Paper 3 Q15
15 A mobile phone takes 2 hours to charge from empty.
When the phone is being charged, the current flow into the phone
- starts at full current flow (100%)
- continues at full current flow for a period of time
- gradually decreases until the phone is fully charged.
This is shown on Graph A below.
Graph A
Graph B
Megan’s phone is empty of charge.
She starts to charge her phone at 10.00 am
(a) Using Graph A,
estimate the time when the current flow starts to decrease. [2 marks]
(b) Using Graph A and Graph B,
estimate the percentage charge in the phone when the current flow is 40% [1 mark]
(c) Using Graph B,
estimate the rate of increase in the percentage charge when the phone has 90% charge. [2 marks]
| Answer | Mark | Comments |
|---|---|---|
| Vertical line drawn from correct point on graph to horizontal axis or [25, 27] | M1 | implied by mark on horizontal axis |
| [10.25, 10.27] (am) | A1 | SC1 10.23 (am) |
| Answer | Mark | Comments |
|---|---|---|
| 80 | B1 |
| Answer | Mark | Comments |
|---|---|---|
| Correct tangent drawn where charge is 90% | M1 | |
| Correct gradient for their tangent | A1 |
Additional guidance
| No tangent drawn | M0A0 |