Question 44
HA student investigates how the efficiency of an electric motor depends on the mass of the load it lifts.
The Figure shows the apparatus.
Figure
The motor raises each load through a height of 0.80 m.
The joulemeter measures the total energy supplied to the motor.
The Table shows the results.
Table
| Mass of load in kg\text{kg}kg | Total energy supplied to the motor in J\text{J}J |
|---|---|
| 0.10 | 8.0 |
| 0.20 | 8.8 |
| 0.30 | 9.6 |
| 0.40 | 10.4 |
| 0.50 | 11.2 |
Gravitational field strength (ggg) = 10 N/kg
Explain how the efficiency of the motor changes as the mass of the load increases.
You should use calculations based on the data in the Table in your answer.
8.3 Power and efficiency Questions
128 exam-style questions on Edexcel GCSE Physics 8.3 Power and efficiency, covering 8.3.1 Power and 8.3.2 Efficiency. Each one has a worked solution and a mark scheme showing where the marks go.