Que 1: true of false a) Both silicon and germanium atoms have four valances electrons b) When forward-biased , a diode has a very high resistance c) A zener diode is designed to operate in the forward-bias region and has higher reverse breakdown voltage level than regular diode Write the word or phrase that best completes each statement or answers the questions: d) In semiconductor, in addition to the electron flow, there is also another kind of charge flow referred as………………. e) A silicon diode in placed in series with 2kΩresistor and a 14 V dc power supply. The current ID is: i) 6.65 mA ii) 2.2 mA iii)7.5 mA iv) 14 mA f) The series resistor that limits the forward current length through a silicon diode to 8 mA if the power supply voltage is 9.5V is : i) 1.1 kΩ ii) 2.2 kΩ iii) 9.5 mA iv) 4.7 mA FIGURE g) Determine the diode current IZ for the circuit of figure 1-2: assume VZ = 3.9 V i) 8.1 mA ii) 3.55 mA iii) 24.5 mA iv) 13.64 mA h) Determine the current through a 20 mA yellow LED when the power supply voltage is 15 V the series resistor is 2k ohm and the diode is put in backward. Assume VLED = 2V i) 20 mA ii) 0 mA iii) 10 mA iv) 6.5 mA Write the word or phrase that best completes each statement or answers the questions: i) Zener diode is a p-n junction diode that is desgined for specifc…………………voltage j) ………………………….is the process by which impurity atoms are introduced to the instrisic semiconductor in order to alter the balance between holes and electrons. 1) The average value of s full-wave rectifier with a peak vaue of 17V ia 108V 2) If the frequency of input signal of the full wave reflector is 60Hz, the output frequency is 120Hz 3) The cathode of a zener diode, when conducting is:y i) at 0.7V ii) more positive than anode iii) more negative than anode iv) -0.7V 4) A given transformer with turn ratio 12:1has an input of 115V at 60Hzthe paek output voltage v0 (p) is i) 9.58 V ii) 6.78V iii) 11.5 V iv) 13.55 V FIGURE 2-1 5) The output voltage of V0(DC)for the full wave rectifier of figure 2-1 is i) 18.07 V ii) 12.78 V iii) 8.3 V iv) 5.74 V FIGURE 2-2 6) The voltage V2(P) for the full-wavr bridge rectifier of figure 2-2 is i) 17.37 V ii)1 6.67 V iii) 12.78 V iv) 18.07 V 7) Assume the current I0(DC) in figure is 100mA and C= 2400µF .the ripple voltage vr (p-p) i) 694mV ii) 424 mV iii) 121 V iv) 347 V Use figure 2-3 for questions below: Assume that RS = 75, RL = 160 FIGURE 2-3 8) The output voltage V0 is i) 7.5 V ii) 10 V iii) 8.5 V iv) 12 V Write the word or phrase that best completes each statement or answers the questions: 9) The magnitude of the peak-to-peak ripple voltage vr (p-p) is directly proportional to the output …………………. 10) The ripple voltage at the filter section vr (p-p) can be reduced by increasing the value
Name___________________________________ Period_____ Investigation: Making Waves PART I: Objectives: • Learn vocabulary describing waves • Calculate the speed of a wave • Understand how amplitude affects the speed of a wave • Understand how frequency and wavelength affect the speed of a wave Open this web site: http://phet.colorado.edu/new/simulations/sims.php?sim=Wave_on_a_String You can click on Run Now! to run the simulation online, or Run Offline to save it to your desktop. It might run faster this way. Start by Wiggling the Wrench. Spend about 5 minutes experimenting with the Tension, Manual/Pulse/Oscillate, Fixed/Loose/No end, and changing the Amplitude, Frequency and Damping. Click on Show Rulers and Timer. Practice moving the rulers around and starting/resetting the timer. Click on the Pause/Play and Step buttons to see how they work. Use these settings: Pulse, Amplitude=50, Pulse Width=35, Damping=0, Tension at High and No End. NOTE that the amplitude is just a relative scale (not centimeters). Send a single pulse down the string. This is called a TRANSVERSE PULSE. Watch the motion of the green dots. 1. As the pulse goes by from left to right, in what direction does the string move? ________________________________________________________________________________________________________________________________________________ 2. A definition of TRANSVERSE is “lying across”. Why is TRANSVERSE a good name for the wave you just observed? ________________________________________________________________________________________________________________________________________________ Make another pulse, and then PAUSE the wave. Use the vertical ruler to measure the amplitude of the wave in centimeters. This is the distance from the dotted orange line to the crest of the wave. Record the amplitude in Table 1 in the first row. Now, measure the time for a pulse to travel 100 cm. To do this: • Reset the clock to 0:00 and reset the generator • Click Pause/Play—it should say PAUSED on the screen • Click Pulse • Click Pause/Play again to start a timed pulse. Pause again just as the crest (peak) of the pulse touches the window 100 cm away. Record the time for a pulse to travel 100 cm in Table 1. Run 3 time trials, and record in the table. Calculate the average time. Now, measure the amplitude and timing of pulses for two other amplitudes (one smaller than 50, one larger than 50). Do three trials at each amplitude and calculate the average times. Calculate the average wave speed for each of the three amplitudes. See below for a sample calculation. Table 1 Your measured amplitude, cm Time for pulse to travel 100 cm, seconds Average time, seconds Speed=length of string / average time Example of speed calculation: Speed = string length/ average time Speed = 100 cm/2 seconds = 50 cm/second 3. How does the amplitude of a wave affect the speed of a wave? ________________________________________________________________________ Use these settings: Oscillate, Fixed end. Try amplitude=20, frequency=51, damping=0. The result is called a periodic wave. 4. Describe the appearance of the wave you created. ________________________________________________________________________________________________________________________________________________________________________________________________________________________ You should see waves that do not move along the string. You will also see points where the string does not move at all. These waves are called STANDING WAVES. The points where the wave doesn’t move are called NODES. Pause the simulation. 5. Draw the standing wave in the box below, labeling the AMPLITUDE, WAVELENGTH and NODES of a standing wave. Use these settings: Amplitude=20, Frequency=50, Damping=0, Oscillate, No End. Reset the clock. You can also measure the wave frequency. To do this, you should pair up with another student if possible. Watch the piston go up and down to make the wave. One up and down motion represents one wave. Use the clock to measure the time required for 10 complete cycles or waves. You will also need to PAUSE the wave to measure the wavelength of the wave in centimeters (cm). The frequency of the wave is calculated in the following way: Frequency = 10 waves/# seconds for 10 cycles For example, 10 waves/5 seconds = 2 cycles per second, or 2 Hertz. Make several waves by changing the wave frequency—use numbers over 30 on the scale. For each wave, measure the wavelength using the ruler. Now, calculate the frequency. See the example in the first row of Table 2. Record the wavelength and frequency of three waves with different wavelengths. Wavelength (cm) Frequency (cycles/second or Hertz) Speed (cm/s) = Wavelength x frequency 33 cm 10 waves/5.45 sec = 1.8 Hertz 33 cm x 1.8 Hertz = 59.4 cm/second Based on the equation used to calculate the speed of a wave, answer questions 6 and 7. 6. If you increase the wavelength of a wave, how does the speed change? ________________________________________________________________________________________________________________________________________________ 7. If you increase the frequency of a wave, how does the speed change? ________________________________________________________________________________________________________________________________________________ Part II: Objectives: • Interpret a 2D top view picture of a wave • Identify areas of constructive and destructive interference in 2D • Predict the behavior of water, sound, or light when you have two sources o What will happen in constructive areas o What will happen in destructive areas 1) Open the “Wave Interference” simulation from the PhET website (in Sound & Waves) 2) On the water simulation, what does the crest (peak) of the wave look like in the top view? What does the trough look like? 3) When you add two drips, what changes about the waves’ patterns? 4) What does the wave look like in the area that the two waves constructively interfere? Describe both the top view and what the side view would look like. a. TOP: b. SIDE: 5) What does the wave look like in the area that the two waves destructively interfere? Describe both the top view and what the side view would look like. a. TOP: b. SIDE: 6) Switch to the sound simulation. a. What do you think will happen when you put two speakers next to each other? b. Why do you think this will happen? c. Try it (putting two speakers together) and tell me what happened. 7) Now switch to the light simulation. a. What do you think will happen when you put two light sources next to each other? b. Why do you think this will happen? c. Try it (putting two light sources together) and tell me what happened. d. What happens when you use one light source and two slits? 8) What is similar about all three of these simulations (i.e. water, sound & light)? 9) How do I know that these things are waves and not particles? (Think about what would happen in the two slit experiment if they were particles).
ELEC153 Circuit Theory II M2A4 Lab: AC Parallel Circuits Introduction In this experiment we work with AC parallel circuits. As we did in the AC series circuits lab, the results obtained through Transient Analysis in MultiSim will be verified by manual calculations. Procedure 1. Figure 1 is the circuit we want to analyze.The voltage source is 24 volts peak at 1000 Hz. Figure 1: AC parallel circuit used for analysis using MultiSim Unlike the series circuit, there is no resistor in series with the voltage source that allows us to plot the current by taking advantage of its in-phase relationship. So, in order to measure the current produced by the source (total current) add a 1 Ohm resistor in series with the source. This small resistor will not affect the calculations. Figure 2: Arrangement for analyzing the current waveforms 2. Run the simulations and with the oscilloscope measure both the source voltage and the voltage across the resistor. You should get a plot similar to the following graph: Figure 3: Source voltage (red) and source current (blue) waveforms 3. From the resulting analysis plot, determine the peak current. Record it here. Measured Peak Current 4. Determine the peak current by calculation. Record it here. Does it match the measured peak current? Explain. Calculated Peak Current 5. Calculate the phase-shift. Using the method presented in the last lab, measure the time difference at the zero-crossing of the two signals. Record it here. Time difference 6. From the resulting calculation, determine the phase shift by using the following formula Record it here. Measured Phase Shift 7. Determine the phase shift by calculation. Record it here. Does it match the measured phase shift? Explain. Calculated Phase Shift 8. Change the frequency of the voltage source to 5000 Hz. Re-simulate and perform a Transient Analysis to find the new circuit current and phase angle. Measure them and record them here: Measured Current Measured Phase Shift 9. Perform the manual calculations needed to find the circuit current and phase shift. Record the calculated values here. Do they match the measured values within reason? What has happened to the circuit with an increase in frequency? Calculated Current Calculated Phase Shift 10. Replace the capacitor with a 0.8 H inductor. Set the source frequency back to 1000 Hz. Perform Transient Analysis and measure the current amplitude and phase shift. Record them here: Measured Current Measured Phase Shift 11. Perform the manual calculations needed to find the circuit current and phase shift. Record the calculated values here. Do they match the measured values within reason? Calculated Current Calculated Phase Shift 12. Change the frequency of the voltage source to 5000 Hz. Re-simulate and perform a Transient Analysis to find the new circuit current and phase angle. Measure them and record them here: Measured Current Measured Phase Shift 13. Perform the manual calculations needed to find the circuit current and phase shift. Record the calculated values here. Do they match the measured values within reason? What has happened to the circuit with an increase in frequency? Calculated Current Calculated Phase Shift Write-up and Submission In general, for each lab you do, you will be asked to setup certain circuits, simulate them, record the results, verify the results are correct by hand, and then discuss the solution. Your lab write-up should contain a one page, single spaced discussion of the lab experiment, what went right for you, what you had difficulty with, what you learned from the experiment, how it applies to our coursework, and any other comment you can think of. In addition, you should include screen shots from the MultiSim software and any other figure, table, or diagram as necessary.
suppose that you wish to construct a simple AC generator with a peak output of 12 V when rotated at 60 Hz. A magnetic field of 0.0497 T is available. If the area of the rotating coil is 0.01 m, how many turns are needed ? 1) 16 2) 32 3) 64 4) 128 5) 256
An electric generator produces a peak voltage of 10.0 V when turning at 3000 RPM what peak voltage would be same generator provide if it were turning at 9000 RPM ? 1) 1.1 v 2) 3.3 v 3) 10 v 4) 30v 5) 90v
Where: λmax = peak wavelength in the T = temperature … Read More...
Biomedical Signal and Image Processing (4800_420_001) Assigned on September 12th, 2017 Assignment 4 – Noise and Correlation 1. If a signal is measured as 2.5 V and the noise is 28 mV (28 × 10−3 V), what is the SNR in dB? 2. A single sinusoidal signal is found with some noise. If the RMS value of the noise is 0.5 V and the SNR is 10 dB, what is the RMS amplitude of the sinusoid? 3. The file signal_noise.mat contains a variable x that consists of a 1.0-V peak sinusoidal signal buried in noise. What is the SNR for this signal and noise? Assume that the noise RMS is much greater than the signal RMS. Note: “signal_noise.mat” and other files used in these assignments can be downloaded from the content area of Brightspace, within the “Data Files for Exercises” folder. These files can be opened in Matlab by copying into the active folder and double-clicking on the file or using the Matlab load command using the format: load(‘signal_noise.mat’). To discover the variables within the files use the Matlab who command. 4. An 8-bit ADC converter that has an input range of ±5 V is used to convert a signal that ranges between ±2 V. What is the SNR of the input if the input noise equals the quantization noise of the converter? Hint: Refer to Equation below to find the quantization noise: 5. The file filter1.mat contains the spectrum of a fourth-order lowpass filter as variable x in dB. The file also contains the corresponding frequencies of x in variable freq. Plot the spectrum of this filter both as dB versus log frequency and as linear amplitude versus linear frequency. The frequency axis should range between 10 and 400 Hz in both plots. Hint: Use Equation below to convert: Biomedical Signal and Image Processing (4800_420_001) Assigned on September 12th, 2017 6. Generate one cycle of the square wave similar to the one shown below in a 500-point MATLAB array. Determine the RMS value of this waveform. [Hint: When you take the square of the data array, be sure to use a period before the up arrow so that MATLAB does the squaring point-by-point (i.e., x.^2).]. 7. A resistor produces 10 μV noise (i.e., 10 × 10−6 V noise) when the room temperature is 310 K and the bandwidth is 1 kHz (i.e., 1000 Hz). What current noise would be produced by this resistor? 8. A 3-ma current flows through both a diode (i.e., a semiconductor) and a 20,000-Ω (i.e., 20-kΩ) resistor. What is the net current noise, in? Assume a bandwidth of 1 kHz (i.e., 1 × 103 Hz). Which of the two components is responsible for producing the most noise? 9. Determine if the two signals, x and y, in file correl1.mat are correlated by checking the angle between them. 10. Modify the approach used in Practice Problem 3 to find the angle between short signals: Do not attempt to plot these vectors as it would require a 6-dimensional plot!