Physics (AS & A Level) · Feb / March 2019 · Paper 12 · Question 4

A digital balance is used to weigh ingredients in a laboratory. When a weight is applied to the digital balance, an electronic circuit generates a current which is then converted into a digital readout on the display. The electronic circuit gives a current of 2.0 mA when a weight of 30 N is applied, and a current of 0.5 mA when a weight of 5 N is applied. Which calibration curve could represent this circuit?

1. Agraph A: current/mA against weight/N, curve concave down from (0,0) to (30,2)
2. Bgraph B: current/mA against weight/N, curve decreasing from (0,2)
3. Cgraph C: current/mA against weight/N, curve concave up from (0,0) to (30,2)
4. Dgraph D: current/mA against weight/N, curve concave down from (0,2) to (30,0)

As printed in the paper