Questions tagged [homework]
Use this tag if the question you are asking is an assignment or homework with which you require assistance. EE.SE is not a homework answering service, so make sure you show what you have attempted so far and are specific as to where you have gotten stuck.
576
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Is this a legitimate way to determine the Thevenin's voltage and resistance? [duplicate]
I'm sorry I'm reposting, but I'm not sure if my previous question got "closed", since there were some error messages for me at least. Feel free to remove the previous one if it's still open ...
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1
vote
1
answer
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How do I go about solving the current I1 using Thevenin's Theorem?
I understand from here I'm supposed to solve the current flowing through \$R_1\$. So I have to remove the \$R_1\$ and add terminals A and B and solve the resistance between them? Would it be easier ...
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0
votes
1
answer
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Solving for V and I in a diode circuit by making assumptions
I want to make sure I understand the solution to this problem from my textbook. The goal is to solve for V and I in the circuit below:
They start by assuming that both diodes are conducting and solve ...
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1
vote
3
answers
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Transient response of capacitor connected to current source with no resistor
I have this HW problem:
It has me completely stumped because the usual equation for the transient response of a capacitor assumes the circuit has a voltage source, not a current source, and requires ...
0
votes
4
answers
88
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Power Dissipation in an AC Circuit
I'm seeking clarification on power dissipation in an AC circuit with a specific scenario in mind.
I was able to calculate the RMS current through the AC Mains = √10 A
Considering that the upper ...
0
votes
1
answer
40
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Applying KVL to a grounded MOSFET circuit
I'm rather confused as to how to how this circuit doesn't violate KVL:
The two node voltages on the right side of the loop add to -4.16V, which means the voltages on the left should add to 4.16V, ...
4
votes
3
answers
501
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Overdrive voltage of NMOS vs PMOS
I'm confused whether the overdrive voltage for an NMOS/PMOS transistor is supposed to be
$$V_{ov} = V_{gs}-V_t,$$
$$V_{ov} = V_{sg} - V_t,$$
or
$$V_{ov} = V_{gs}-|V_t|$$
and whether it matters ...
0
votes
0
answers
45
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Need help in understanding circuit of PMOS reverse
Given 2 PMOS enhancement: Vdd = 5 V, k1/k2 = 9, Vt = -1.
I'm trying to find Voh, Vol, Vil, Vih.
I would appreciate help and explanation.
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votes
3
answers
116
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Getting wrong answer for mesh current analysis
The circuit diagram is given below, I keep getting the wrong answer for the mesh currents, I always get -1 for first loop and -7 for second loop. Therefor Ix comes out to be 6 which is wrong. It ...
0
votes
2
answers
53
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KCL in a particular node (problem)
Above is an AC circuit in which terminals A and B are used to connect to a load. I am asked to find the equations for currents coming into and out of nodes 1 and 2 (using KCL).
I had no trouble ...
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How do I calculate Io and n from the Shockley equation given two operation points?
In this exercise I'm given the Vd and Id in two operation points and I need to calculate Io and n from the Shockley equation. I've tried isolating Io and replacing it in the other equation but then I ...
0
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0
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59
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MOSFET circuit operating point
Yesterday I spent about two hours trying to calculate the operating point of this circuit without success but I can't accept my defeat.
The exercise asks to:
"Complete" the operating point ...
0
votes
1
answer
100
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Need help to find Thevenin resistance and Thevenin voltage
Here is the question I am trying to solve(there are 2 things I need to find. These are Vth and Rth):
Here is my attempt: ( please check Vth if it is true )
I couldn't find Thevenin resistance at all
...
0
votes
1
answer
74
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Why do I get two different transfer functions for the same gain?
I'm trying to derive the expression for \$ A_X = \frac{V_X}{V_{IN}}\$ but I'm getting two different ones relatively to the \$KCL\$ I use to calculate it.
With \$ KCL \; A)\; -\frac{V_{IN}}{R_S} = \...
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votes
0
answers
50
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Network synthesis. What kind of knowledge do I need to solve this question?
Below is my homework assignment related to network synthesis. I have never seen this type of question before and no idea how to start the solution. Can somebody give me some kind of hint to start it ...
0
votes
0
answers
63
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Triangular-wave to sinewave converter with symmetrical circuit
I don't think I have a solid approach when analyzing complex circuits like these. I hope some of you can give me general directions and help me tackle this one.
Given that the diodes are ideal and \$...
0
votes
0
answers
100
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How to design a PI/PID controller with a given bandwidth and phase margin?
I've read the article, Introduction: PID Controller Design, which explained really well the effect each branch of the controller has on the rise time, settling time, overshoot, and error, which gives ...
0
votes
1
answer
90
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Band-pass filter characteristic parameters and maximum gain frequency
I think I have a big conceptual gap, I hope someone can clarify things to me.
The exercise asks the following:
The analytic expression of the gain \$A_v\; = \; \frac{V_o (j\omega)}{V_{in} (j\omega)}\...
2
votes
1
answer
38
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Relation between overhead and aggregated transmission data rate
My homework asks me to calculate the overhead and aggregated transmission data rate of a RS(\$n\$, \$k\$) code at \$M\$ Gb/s. I know that overhead is the additional data added to correct errors, which ...
0
votes
2
answers
74
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How to find power delivered by current source
I need to find power delivered by current source. I tried using node analysis but there is a voltage source and it can't be transformed to current source as there is no resistor in series. Can you ...
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0
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32
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Matching micro-strip line to load and generator
I have the following system.
I need to add stubs/ reactive components to the trace (L2) to match the generator to the load.
I understand that due to Z_trace being a micro-strip that its consists of ...
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0
votes
2
answers
202
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Calculating the magnitude and phase angle of a transfer function [closed]
How do I find the magnitude and phase angle of this transfer function?
$$H(j\omega)=\frac{1}{(j\omega+6)^2}$$
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2
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79
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Common emitter question
Consider the common-emitter (CE) amplifier below:
Given: VCC = 10 V, RC = 3 kΩ, RBB = 100 kΩ, β = 100, VT = 25 mV, VBIAS = 3 V, VBE (ON) = 0.7 V, r0 = ∞.
DC analysis: Prove that transistor Q1 is ...
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0
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1
answer
272
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Unbalanced Wheatstone bridge with a capacitor in the middle
I have to find the amount of charge stored in a capacitor after a significant amount of time when $$ R_{1}=1 k \Omega, R_{2}=8 k \Omega, R_{3}=4 k \Omega, R_{4}=2 k \Omega,C=1\mu F,V=10V$$ There is no ...
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2
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54
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How do I find the value of resistor 4? [closed]
Assuming this is balanced: if R1 is 130 Ω, R2 is 240 Ω, and R3 is 65 Ω, then what is R4?
0
votes
1
answer
58
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Trouble solving a specific KVL KCL question
Now I know this is newbie-ish kinda question but I was going over the basics of KCL and KVL, and encountered this problem:
For 1., I determine the drop using Ohm's law, ie. 2V
for 2-4 things get ...
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2
votes
2
answers
274
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Total resistance of circuits that resemble Wheatstone bridges
I need to find the total resistance that is seen from terminals a and b for the three circuits below.
I found that all of the circuits have the same total resistance Rt=R (not sure if the answer is ...
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1
vote
1
answer
42
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RL circuit phasor notation problem
I am asked to find the voltage across the resistor and the inductor(in phasor notation).
These are the steps I took
$$ v_{R}=\frac{R}{R+jX_{L}}v $$
$$ v_{R}=\frac{vR}{R+jX_{L}}\cdot \frac{R-jX_{L}}{R-...
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votes
4
answers
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Inverting op-amp problem
Down below is an inverting op-amp circuit with a capacitor C connected to the non-inverting input. I have to find the voltage at point A and express it using vin, C and R.
I tried to solve the ...
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vote
4
answers
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Why can the \$I_c\$ be written as \$\frac{V_{CC}-5V}{R1+R3}\$?
Why is it \$I_C=\frac{V_{cc}-5V}{R1+R3}\$ and not \$I_C=\frac{V_{cc}-5V}{R1}\$?
I am a little bit confused with it, can anyone tell me the reason?
simulate this circuit – Schematic created ...
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1
answer
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Calculate the potential difference for each capacitor (problem)
Below we have an AC circuit with diodes connected in parallel and a few capacitors in between. Von=1V and Ron=0 for each diode. I am asked to find the potential for each of the capacitors when ...
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votes
1
answer
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Security issue for landing doors and cabin doors in an elevator control board (PIC16F877)
I am working on a control board for an elevator as part of my final year project. I am currently working on the safety aspect for the landing doors and cabin doors, and I am using Proteus to simulate ...
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2
votes
1
answer
90
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Step response RC Circuit problem
(Example problem from a textbook) A unit step function u(t) is added between the terminals 1-1'. I am asked to find the voltage vo(t) between 2-2'.
If we convert the circuit above to a s-domain ...
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vote
0
answers
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RL circuit graph problem
An inductor and a resistor are connected in series. I have to find the resistance R, inductance L, voltage across the inductor V and initial flux linkage from the graphs (c) and (d).
There was no ...
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votes
2
answers
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Am I applying KVL correctly to this very simple circuit?
We have this circuit:
I make the following assumptions about the current:
Such that $$I_1+I_2+I_3=0$$ at the blue junction. I then draw two loops, l_1 and l_2:
which yields the equations
$$-12 -...
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3
votes
1
answer
269
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How to solve combination circuits? [closed]
We were asked to find the total current and voltage, and also the individual currents and voltages of each resistor.
Please teach me the steps for solving each of the circuits, and if you have any ...
1
vote
0
answers
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I know the concept of per unit, but I don't know why am i wrong
A generator which apparent power is \$120MVA\$,and voltage is \$19.5kV,X_s=1.5p.u.\$. Now it is connected a transformer then connected to a transmission line. The rated value transformer is \$150MVA,...
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3
votes
1
answer
66
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Equivalent circuit problem
I need to find the values E1,E2,R1,R2,R3 such that circuit (b) becomes equivalent to circuit (a) according to nodes a,b,c.
Using the superposition theorem I found that the potential difference between ...
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0
votes
1
answer
129
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How to calculate current in a complex circuit? [closed]
Regarding a) How do I calculate the current for I1?
Regarding b) How do I calculate IA?
I have calculated I3 and I4 by using I = V/R and got the following:
I3 = 5 V/10000 Ω and
I4 = 5 V/100000 Ω
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0
answers
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Power supplied by the current and voltage sources (problem)
I have to find the power supplied by the current and voltage sources below. The correct answers are as follows.
$$P_{I}=\frac{1}{2}E_{s}I_{s}+\frac{3}{2}RI_{s}^{2}$$
$$P_{E}=\frac{1}{2}E_{s}I_{s}-\...
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2
answers
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How to find R and L in a circuit when you know tau and steadystate/stationary value
I am given the circuit below:
I know that the equation governing the circuit is:
$$
I(t) = I_{0}e^{{\frac{{-R}}{L}t}}
$$
I also know that the time constant τ is given as:
$$
\tau = \frac{{L}}{R}
$$
...
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3
answers
152
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What is the best method for solving this circuit analysis problem in the S-domain?
I'm just curious what the best method for solving for voltage across the capacitor might be.
My initial idea was to use nodal analysis but I ran into a roadblock in that I am not entirely sure how the ...
0
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2
answers
53
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How to make a circuit of 6 lights connected to a single battery, with each light having its own switch [closed]
I have a school assignment on how to make a circuit with 6 lights connected to a single battery, with each light having its own switch. I'm wondering how to do this, and I'm hoping for guidance.
0
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1
answer
70
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Connections in 3-phase AC circuits
Does the supply voltage refer to the line voltage or the phase voltage here?
-1
votes
1
answer
66
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Transformer's Hysteresis Loss
Relation between hysteresis loss and the magnetic field intensity is given but I don't know how the loss is affected by the frequency of the current. What is the relation between the frequency and ...
0
votes
2
answers
61
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Maximum flux in transformers
What is meant by maximum flux here? How can I calculate it? I could calculate the rest of the question comfortably.
3
votes
1
answer
161
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Resonance in AC circuits
Derive the frequency for resonance condition in the following circuit.
My perception is that I need to nullify the j part of equivalent impedence, is that correct?
Question:
My approach:
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0
answers
35
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Need help categorizing keywords and concepts for two different scenarios
I am currently working on a project that involves categorizing certain keywords and concepts into two different scenarios. I am having a bit of trouble determining which scenario each keyword belongs ...
0
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0
answers
44
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Finding the value of supply voltage in this RLC circuit
We need to find the value of V, Power Factor, and Power Absorbed in the circuit.
I am stuck at resolving the two parallel branches.
I started out by labeling the impedances of the three given ...
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0
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1
answer
125
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Switched capacitors in an op-amp circuit
I am having trouble solving part (b) of this task.
I would expect to achieve charge conservation equations, but considering that the inverting input of the op-amp is shorted with the output terminal ...
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