An investigation is carried out to find how the strength of an electromagnet varies with the current flowing through its coil. The electromagnet attracts an iron bar suspended from a spring, and the resulting extension of the spring is measured.
The graph below shows the results of this investigation.
The current in the coil is increased from 0.4 A0.4\text{ A}0.4 A to 1.2 A1.2\text{ A}1.2 A. Determine the increase in the extension of the spring.
Calculate the increase in the force acting on the spring when the current in the coil increases from 0.4 A0.4\text{ A}0.4 A to 1.2 A1.2\text{ A}1.2 A.
Use the equation: force=spring constant×extension\text{force} = \text{spring constant} \times \text{extension}force=spring constant×extension The spring constant is 0.45 N/cm0.45\text{ N/cm}0.45 N/cm.
The motor effect Questions
Practise AQA GCSE Physics The motor effect with exam-style questions for Foundation and Higher tier. 25 questions covering Electromagnetism, Fleming's left-hand rule (HT only), Electric motors (HT only), and Loudspeakers (physics only) (HT only), matched to the AQA GCSE Physics (8463) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.