Microphones (ht Only) (GCSE Physics)

A moving-coil microphone has a coil of many turns attached to the diaphragm. Which change would increase the amplitude of the voltage produced for a given sound pressure?

In audio systems, a transformer is sometimes used between a moving-coil microphone and a microphone preamp. Which is a correct reason for using such a transformer?

In Faraday’s law emf = -N dF/dt, if a microphone’s coil has N turns and the diaphragm causes the flux through each turn to change sinusoidally with time at fixed amplitude, how does induced emf scale with N?

A dynamic microphone’s coil moves more for low frequencies than for high frequencies with the same sound pressure. Which statement about the microphone’s frequency response is correct?

A moving-coil microphone shows nonlinearity at very high sound pressure levels. Which physical cause is most likely?

A microphone’s output cable picks up a time-varying magnetic field from a nearby loudspeaker transformer, producing hum. Which engineering solution targets the problem most directly?

A moving-coil microphone is used in a windy outdoor location. Which technique best reduces wind-induced low-frequency noise while preserving speech intelligibility?

If you double the speed at which the coil cuts magnetic flux (for example, due to a louder sound producing larger diaphragm velocity), what happens to the instantaneous induced emf (ignoring nonlinearities)?

Which factor most directly increases the induced emf in a microphone for a given diaphragm displacement amplitude?

Why do moving-coil microphones generally tolerate high humidity and physical shock better than condenser microphones?

Which design change will reduce a dynamic microphone’s output impedance to better match mixing desk inputs?