Question 1: Microphones convert sound waves into electrical signals using the generator effect, which involves electromagnetic induction. When a coil moves within a magnetic field, an emf is induced, allowing sound to be recorded or amplified.

Answer: Microphones use electromagnetic induction where a coil moves in a magnetic field to induce an emf, converting sound into electrical signals.

Question 1: Define electromagnetic induction.

Answer: Electromagnetic induction is the process of generating an emf across a conductor when it experiences a changing magnetic flux.

Question 2: Describe how a moving coil within a magnetic field produces an electrical signal in a microphone.

Answer: The coil moves in response to sound vibrations, changing the magnetic flux through it, which induces an emf that creates an electrical signal.

Question 1: A microphone coil with 200 turns is placed in a magnetic field of flux density 0.02 Tesla. If the coil experiences a change in magnetic flux of 0.001 Weber in 0.01 seconds, calculate the induced emf in the coil. Use the formula emf = N ΔΦ / Δt.

Answer: emf = (200 × 0.001) / 0.01 = 20 volts

Question 1: Identify three variables that affect the amount of emf induced in a microphone coil during operation.

Answer: Number of turns in the coil, strength of the magnetic field, and velocity of the coil movement.

Question 2: State two safety precautions when handling microphones that operate on electromagnetic principles.

Answer: Ensure the equipment is properly grounded to prevent electric shocks and avoid exposing the device to strong magnetic fields that could damage components.

Question 1: A microphone's coil experiences a change in magnetic flux of 0.0005 Weber in 0.005 seconds. How does increasing the number of turns in the coil from 100 to 300 affect the induced emf, assuming all other factors remain constant?

Answer: The emf will increase proportionally with the number of turns; tripling the turns from 100 to 300 will triple the induced emf.

Question 2: Explain how a microphone can be used as a component in a modern audio recording device, considering the generator effect.

Answer: A microphone uses electromagnetic induction where sound waves cause a coil to move within a magnetic field. This movement induces an emf proportional to the sound's vibrations, converting acoustic energy into electrical signals. These signals can then be amplified, recorded, or transmitted, making microphones essential in audio recording technology, telephony, and live sound systems.