A-LevelPhysicsElectric fieldsMay/June 2018Paper 4 Q65 Marks
6 (a) State what is meant by electric field strength. (b) An isolated metal sphere A of radius 26cm is positively charged. Sphere A is shown in Fig. 6.1. [Figure 6.1] Electrical breakdown (a spark) occurs when the electric field strength at the surface of the sphere exceeds 2.0 × 10⁴ Vm⁻¹. Calculate the maximum charge Q that can be stored on the sphere. Q = .............................................. C (c) A second isolated metal sphere B, also with charge +Q, has a radius of 52 cm. Calculate the additional charge, in terms of Q, that may be stored on this sphere before electrical breakdown occurs. additional charge = ..............................................
📋 Examiner Report & Trap Analysis
Common mistake: 62% of candidates selected the distractor because they confused... The examiner specifically designed this question to test whether students can differentiate between... To secure full marks, candidates must demonstrate...
🎯 Mark Scheme Breakdown
Award 1 mark for identifying the correct principle. Award 1 mark for showing clear working. Common errors include failing to convert units and misreading the scale. The examiner report notes that only 34% of candidates achieved full marks on this question.
🔒
Unlock the Examiner's Analysis
Sign up for free to reveal the full examiner report, trap analysis, and mark scheme breakdown for this question.
Sign Up Free to Unlock →Join thousands of Cambridge students already using Oracle Prep