WAEC Physics 2021 Objective — Question 39
Question 39 of 50 from the West African Examinations Council (WAEC) Physics 2021 Objective paper, with the correct answer and a full explanation.
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39. Which of the following statements about a loudspeaker is correct except that
- A. it contains a permanent magnet
- B. sound signal is converted to a varying current signal that enters the speech coil
- C. the current in the speech coil creates a magnetic force on the coil
- D. the magnetic force on the speech coil is uni-directionalCorrect
Explanation
In a loudspeaker, the current in the speech coil alternates, so the resulting magnetic force is NOT uni-directional — making this statement the incorrect one.
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