ELECTRIC MOTORS AND ELECTROMAGNETIC INDUCTION
3 marks · EasyA loudspeaker converts electrical energy into sound using the motor effect.
Name the part of the loudspeaker that moves to create sound waves.
State what causes this part to move.
Briefly explain why the motion of this part can change direction.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) The cone (or paper cone, speaker cone)
(b) A force from the interaction of the current in the coil and the magnetic field
(c) The current in the coil changes direction, so the force changes direction
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Correctly names the cone as the moving part.
B1 (b) · 1 mark · States force on coil due to current and field.
B1 (c) · 1 mark · Explains that the current reverses/vibrates so the force reverses.
Worked solution
a) The cone (vibrating cone). b) The force from the current in the coil and the magnetic field. c) The current changes direction, so the force and cone movement change direction.