The following problems are from both Lathi's Text and other sources. *1. From the definition of average (dc) value, find the average values of the following signals, x(t), y(t) and z(t): x(t) A sin(\omega t) A \frac{A}{t}, \alpha > 0 z(t) 2 t t 0 \frac{T}{2} T 0 0 2 3 5 7 8 *2. a) Find the energy, $E_x$, of the following signal: x(t) 4 0 2 4 t Next, using the definition of energy, find the energy of y(t) = (-c)x(-t-1) in terms of $E_x$. (Note: assume "c" to be a constant) b) Compute the energy of the signal, z(t) = \begin{cases} 3e^{-2t-j3t}, & \text{for } t \ge 0\\0 & \text{for } t \le 0 \end{cases} *3) a) Find the RMS values of the waveforms, x(t) and z(t), shown in Problem 1 above. b) From the values of $x_{dc}$ and $x_{RMS}$ found above, find the RMS value of $x_1(t) = x(t) - x_{dc}$. c) Using the known properties of the power of a sum orthogonal signals, find the RMS values of the following signals: i) p(t) = 3 - 4cos(20\pi t + \frac{\pi}{3})sin(10t - \frac{\pi}{5}) ii) q(t) = 2 - sin^2(10t) iii) r(t) = 2e^{-2t}cos(10t) - 3
Added by Tammy R.
Close
Step 1
Step 1: Read through the text carefully to check for any spelling or typographical errors. Show more…
Show all steps
Your feedback will help us improve your experience
Dominador Tan and 70 other Physics 102 Electricity and Magnetism educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
You may wish to review Section 13.5 on the transport of energy by sinusoidal waves on strings. Figure $\mathrm{P} 24.13$ is a graphical representation of an electromagnetic wave moving in the $x$ direction. We wish to find an expression for the intensity of this wave by means of a different process from that by which Equation 24.26 was generated. (a) Sketch a graph of the electric field in this wave at the instant $t=0$, letting your flat paper represent the $x y$ plane. (b) Compute the energy density $u_{E}$ in the electric field as a function of $x$ at the instant $t=0 .(\mathrm{c})$ Compute the energy density in the magnetic field $u_{B}$ as a function of $x$ at that instant. (d) Find the total energy density $u$ as a function of $x,$ expressed in terms of only the electric field amplitude. (e) The energy in a "shoebox" of length $\lambda$ and frontal area $A$ is $E_{\lambda}=$ $\int_{0}^{\lambda} u A d x .$ (The symbol $E_{\lambda}$ for energy in a wavelength imitates the notation of Section $13.5 .$ ) Perform the integration to compute the amount of this energy in terms of $A, \lambda, F_{\max },$ and universal constants. (f) We may think of the energy transport by the whole wave as a series of these shoeboxes going past as if carried on a conveyor belt. Each shoebox passes by a point in a time interval defined as the period $T=1 / f$ of the wave. Find the power the wave carries through area $A$. (g) The intensity of the wave is the power per unit area through which the wave passes. Compute this intensity in terms of $E_{\max }$ and universal constants. (h) Explain how your result compares with that given in Equation 24.26.
Repeat this process by progressively increasing the peak to peak value of your input (100 mV, 250 mV, 1V, 2V). Measure the signal at node A and node B for each applied input source and compare this signal to the peak to peak value of your input signal you applied. What are you expecting to observe and what did you observe? Does this make sense? From these observed signals, what can you conclude about the common mode gain for stage 1. Plot the three signals (the input signal, the signal at node A, signal at node B on the same plot). Do you see any phase difference between the signals? Stage 1 differential gain: To measure the differential gain from stage 1, ground one of the input source (here we have grounded V2) and apply a signal source to V1 as shown in figure 7. As done previously for single stage differential amplifier, apply a sinusoidal voltage source to V1 terminal (pick a frequency 100 Hz). Start with a voltage value of 10 mV and display the input and the output (Here VA-VB) on the same screen. Record the peak to peak values of the input and the output. Repeat this process by progressively increasing the peak to peak value of your input (10 mV, 25 mV, 100 mV, 150 mV). Calculate the gain. This is your differential gain (Gd) for stage 1. Is the gain the same as the expected gain? Comment. Figure 7: Experimental set up for the measurement of differential gain from stage 1. CMRR calculation for the two stage instrumentation amplifier: Repeat the procedure you have employed previously (for single stage CMRR calculation) for the two stage instrumentation amplifier. As done previously, introduce mismatched resistances in stage 2 and see how the CMRR gets degraded? How does this degradation compare to the degradation observed for single stage amplifier?
Adi S.
16.Find the average power in a resistance R = 10 ohms if the current in series form is i = 10sinwt + 5sin 3wt + 2sin 5wt amperes. A. 65.4 Watts B. 645 Watts C. 546 Watts D. 5.46 Watts 17.The current thru an inductor with inductance of 1mH is given as i(t) = 0.010sin10^6t A. What is the voltage across this conductor? A. 100sin10^6t V B. 10cos10^6t V C. 10sin10^6t V D. 100cos10^6t V 18.A circuit has a resistance of 20 ohms and a reactance of 30 ohms. What is the power factor of the circuit? A. 0 B. 0.55 C. 0.832 D. 0.99 19.A two-element series circuit has voltage V = 240 + j0 V and current I = 48 - j36 A. Find the current in amperes which results when the resistance is reduced to 50% of its former value. A. 46.20 + j69.20 B. -46.20 + j69.20 C. 46.20 - j69.20 D. -46.20 - j69.20 20.A 200mH inductor and an 80 ohm resistor are connected in parallel across a 100 V rms, 60 Hz source. By what angle does the total current lead or lag behind the voltage? A. 46.70° leading B. 43.40° leading C. 43.40° lagging D. 46.70° lagging 21.A capacitor in series with a 200 ohm resistor draws a current of 0.3 ampere from 120 Volts, 60 Hz source. What is the value of a capacitor in microfarad? A. 8.7 B. 9.7 C. 6.7 D. 7.7 22.A series RLC circuit has elements R = 50 ohms, L = 8 mH and C = 2.22 microfarads. What is the equivalent impedance of the circuit if the frequency is 796 Hz. A. 50 + j50 Ω B. 50 + j130 Ω C. 50 - j50 Ω D. 50 + j130 Ω
Recommended Textbooks
University Physics with Modern Physics
Physics: Principles with Applications
Fundamentals of Physics
Transcript
18,000,000+
Students on Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD