What is meant by the term 'hair cell'? Discuss briefly their functions and properties. Explain the terms 'critical band' and 'auditory filters' in the context of frequency resolution.

I need proper solution for the following( underdstandable writing and well explained) thank you  What is resonance in LCR circuit? and tell the difference between impedance and resistance?

7. When the automatic gain control voltage of a radio receiver is measured with a vacuum tube voltmeter whose input resistance is 10 M-ohm, it reads 4.5 V. When an ordinary voltmeter whose input resistance is 10 k-ohm is also connected across the AGC voltage source, both meters read 0.40. What is the internal resistance of the AGC voltage source? 8. A phonograph pick up develops an open-circuit emf of 50 mV and has an internal resistance of 1200 ohm. A. What voltage will it develop across a 4 ohms load resistance? B. What value of load resistance must be used to obtain a 75% eff? C. What is the maximum power output of the pickup? 9. What bleeder resistor is required to complete a voltage divider to give 300 v at 40 mA from a 500 V source of emf if the series dropping resistor is 4 k-ohm.

Find the voltage attenuation ratio for a 30 dB attenuator. Show detailed calculation pls.