Loudspeakers (physics Only) (ht Only) (GCSE Physics)

Which equation gives the magnitude of the magnetic force on a straight conductor of length L carrying current I at right angles to a magnetic flux density B?

What design reason explains using a soft-iron pole piece and laminated magnetic structure around the loudspeaker gap (instead of a solid thick metal block)?

A short audio pulse drives a straight section of voice-coil wire of length 0.65 m with a current of 0.020 A in a magnetic field of 0.125 T. Using F = BIL, what is the magnitude of the force on that wire?

In a loudspeaker the “motor effect” is the name commonly given to which phenomenon?

What is the main purpose of the permanent magnet in a moving-coil loudspeaker?

Which of the following explanations correctly states Lenz’s law in the context of a coil moving near a magnet?

Which of the following is the correct definition of an induced magnet?

What is the physical effect that makes the voice-coil (moving-coil) loudspeaker cone move when an audio electrical signal is applied to the coil?

A speaker designer wants to reduce mechanical resonance peaks in a loudspeaker’s response. Which practical measure will help to dampen the resonance?

If a speaker cone must reproduce very high frequencies accurately, what design property of the cone is most important?

A loudspeaker voice-coil that moves through a magnetic field with velocity v will have an emf induced across the coil proportional to which quantity (for a single loop of length L in a uniform B)?