Resonant RLC circuit and in inductance

AI Thread Summary
A resonant RLC circuit can amplify specific frequency bands, with a gain of 0.5 at 200Hz and 4000Hz. To solve for the required inductor value, both the capacitance and inductance must be known, but only resistance is provided. The relationship between the output/input voltage ratio and the unknowns can be established using the resonant frequency formula. Two equations can be formed from the gain conditions at the specified frequencies, leading to a solvable system. Understanding the equivalent impedance in AC circuits is crucial for finding the solution.
Worme
Messages
14
Reaction score
0
1. A resonant RLC circuit can be used as an amplifier for a certain band of frequencies around the resonant frequency. Consider a series RLC circuit as an audio band amplifier with an AC voltage source as the input, and the voltage across the 8.0Ω resistor as the output. The amplifier should have a gain (=output/input ) of 0.5 at 200Hz and 4000Hz . What is the required value of the inductor in Henry?ata

Homework Equations

3. At resonance Xl=Xc and W0=1/(L*C).
Could you explain me how to do?
Thanks.
 
Physics news on Phys.org
Hi W,
Is your problem statement complete ? C isn't mentioneed ?
The section "relevant equations" sure isn't. What have you got that you can use there ?
Make a darwing and post your attempt at solution. Good luck !
 
Yes C is not mentioneed and so is L. But i know that at resonance a RLC circuit has a frequency 1/(2*pi*sqrt(L*C)). So i know f and R.
 
No you don't, because you don't know L and C. You only know R.
What you do know: at the two given frequencies ouput/input voltage has to be 0.5. Write down an expression for this ratio in terms of R, L and C. With two frequencies you have two equations with two unknowns. The rest is math.
 
Ok but what is the relation between frequencies and output/input?
 
Look under: 2. equations. Oops, empty :rolleyes: ! So what do you have in your notes or in your textbook that can help you out here ? It's not that I am playing hide and seek, it's just that I'm not supposed to just hand over the answer, so you'll have to make an effort.

With DC and two resistances it would be easy, right ? Well, what do we have as an equivalent instead of resistance when we are dealing with alternating currents ?
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Thread 'A cylinder connected to a hanged mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top