A-LevelPhysicsAlternating currentsOct/Nov 2021Paper 4 Q58 Marks
An audio signal of amplitude 2.0 µV and frequency 4.2kHz is to be transmitted using a carrier wave of amplitude 10.0mV and frequency 100kHz. Either amplitude modulation or frequency modulation may be used. The amplitude modulation is at a rate of 1 mV µV⁻¹. The frequency modulation is at a rate of 5 kHz µV⁻¹. Complete Table 5.1 to show the maximum and minimum values of the amplitude and of the frequency of the modulated wave for each type of modulation. Table 5.1 amplitude/mV frequency/kHz minimum maximum minimum maximum amplitude modulation frequency modulation
📋 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