physics lab final quiz Exam Questions And Answers Graded A+.

8.1 purpose - correct answer Study resonance in a series inductor-capacitor-resistor (LCR) circuit by examining the voltage across the resistor as a function of frequency of the applied sine wave The amplitude of the ac current (Io) in a series LCR circuit depends: - correct answer On the amplitude of the applied voltage (Vo) and the impedance (Z) of the LCR circuit Upper case letter Io, Vo, VR, VL, VC: - correct answer Represents the amplitudes of the current and voltage Lower case letter I, v, vR, vL, vC: - correct answer Represents the instantaneous values of the current and voltages vL= VLsin(wt+90) - correct answer vC = VCsin(wt-90) - correct answer vR = VRsinwt - correct answer i = Iosinwt - correct answer v = Vosin(wt+theta) - correct answer VL = IoXL - correct answer VC = IoXC - correct answer VR = IoR - correct answer Io = Vo/Z - correct answer Z = sqrt (XL - XC)^2 + R^2 - correct answer tan theta = XL - XC/R - correct answer XL = wL - correct answer inductive reactance XC = 1/wC - correct answer Capacitive reactance R - correct answer Resistance w = 2*pi*f - correct answer Angular frequency f is the linear frequency Theta - correct answer The phase angle between the current I and the voltage v of the source Impedence depends on frequency, thus: - correct answer Current and voltage vary with frequency The current will be maximum when the circuit is driven at its resonance frequency: - correct answer wres = 2pifres = 1/sqrt LC At resonance: - correct answer XL = XC, Z = Zmin = R, Io = Imax = Vo/R, theta = 0, the current i(t) and voltage v(t) are in phase and VR = VRmax = Vo Why is the inductor is ideal? - correct answer Because it only has inductive reactance without resistance Any real inductor: - correct answer Has resistance and therefore resonance VR - VRmax < 0 What will the phase difference between v and vR produce? - correct answer An elliptical pattern on the screen, which is a Lissajous curve At resonance of the series LCR circuit theta = 0: - correct answer Lissajous curve becomes straight line which is the most intuitive and accurate approach for finding the resonance frequency of the series LCR circuit What is a fast Fourier transform? - correct answer An algorithm to compute the discrete Fourier transform (DFT) of a sequence and its inverse. What does a Fourier do? - correct answer Fourier analysis converts a signal from its original domain (often time or space) to a representation in the frequency domain and vice versa. What has Fast Fourier transform been considered? - correct answer The most important numerical algorithm of our lifetime, widely used for many applications, of math, science, engineering What does a sine wave consist of? - correct answer A single frequency only and its spectrum in frequency domain is a single point A sine wave exists over infinite time and never changes The mathematical transform that converts the time domain waveform into the frequency domain - correct answer Fourier transform