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Type: Posts; User: dzafar

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1. ## Thread: Coulomb Gauge vs. Lorenz Gauge

by dzafar
Replies
0
Views
868

### Closed: Coulomb Gauge vs. Lorenz Gauge

Hi there,

I am trying to solve Problem 10.5 from Griffiths Introductionto Electrodynamics. The problem says:

Which of the potentials in Ex. 10.1, Prob. 10.3, and Prob. 10.4 are in the Coulomb...
2. ## Thread: What is the meaning of Skin Depth?

by dzafar
Replies
1
Views
1,107

### Closed: What is the meaning of Skin Depth?

Hello,

My book defines skin depth as "a measure of how far the wave penetrates into the conductor".

Just to double check if I am on the right track of thought, does this mean that since it is a...
3. ## Thread: General Identity of Derivative

by dzafar
Replies
8
Views
2,442

### [SOLVED]Closed: Re: General Identity of Derivative

Okay.. so I figured it out.

My mistake was that I was taking B directly inside the derivative and making it a B^2. The correct way is to apply the product rule for derivative. For simplicity I am...
4. ## Thread: General Identity of Derivative

by dzafar
Replies
8
Views
2,442

### [SOLVED]Closed: Re: General Identity of Derivative

Okay!! I know what I wrote DOES make sense. B is NOT a variable. It is a VECTOR FIELD!!!

Once you understand that it is a vector, then you would see that vector dot the same vector is equal to the...
5. ## Thread: General Identity of Derivative

by dzafar
Replies
8
Views
2,442

### [SOLVED]Closed: General Identity of Derivative

Hello,

I know this is really stupid BUT my mind is still questioning it. I am taking the dot product of magnetic field, B with its derivative:

B.∂B/∂t ................(i)
= ∂B2/∂t ........(ii)...
6. ## Thread: Wein Bridge Oscillators - Diode Stabilization

by dzafar
Replies
11
Views
1,680

### Closed: Re: Wein Bridge Oscillators - Diode Stabilization

Ohh!! So you mean, when the amplitude of Vo < 0.6 both diodes are OFF?
7. ## Thread: Wein Bridge Oscillators - Diode Stabilization

by dzafar
Replies
11
Views
1,680

### Closed: Wein Bridge Oscillators - Diode Stabilization

Hello there,

I cam across Wien Bridge Oscillators (attached below) but am having a hard time understanding why both the diodes are OFF at low signals?

My understanding says: when signal is low...
8. ## Thread: Getting nagative width in Chebyshev Transformer

by dzafar
Replies
0
Views
372

### Closed: Getting nagative width in Chebyshev Transformer

Hi there!

Objective: To design a wideband matching transformer to match a 10 Ω load to a 50 Ω transmission line at a center frequency of 1.0 GHz, matched so that |Γin| < 5%.

Calculate the...
9. ## Thread: Specify component values for a given gain at a given frequency

by dzafar
Replies
2
Views
639

### [SOLVED]Closed: Specify component values for a given gain at a given frequency

Hello there,

Attached below is the question I am trying to solve.

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(a) H(s) = 2sRC -- Is this correct? Does this mean the zero is at the origin? Is the '2' considered gain?
(b) I have...
10. ## Thread: RFID Antenna and Tags

by dzafar
Replies
1
Views
419

### Closed: RFID Antenna and Tags

Hello there,

I am trying to put together an obstacle detection system that detects RFID tags from a minimum distance of 3 m. These tags are to be worn by employees in a warehouse and the reader...
11. ## Thread: Half Wave Rectifier when input voltage is negative

by dzafar
Replies
9
Views
1,385

### [SOLVED]Closed: Re: Half Wave Rectifier when input voltage is negative

Suppose I have an LM741 op amp. What should I look in the datasheet to get that information?

dzafar
12. ## Thread: Half Wave Rectifier when input voltage is negative

by dzafar
Replies
9
Views
1,385

### [SOLVED]Closed: Half Wave Rectifier when input voltage is negative

Hello,

I am new to half-wave rectifiers. Below is a screenshot from my book.

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Can someone please explain why VOL is 2V greater than VEE?

Thanks!

by dzafar
Replies
1
Views
406

### [SOLVED]Closed: Rectangular waveguide

Hi,

I am new to rectangular waveguides. In one question I am given the source freqency, relative permitivity and permeability of the dielectric material and the width and height of the rectangular...
14. ## Thread: Transmission Line Theory Understanding

by dzafar
Replies
2
Views
456

### [SOLVED]Closed: Transmission Line Theory Understanding

Hello all,

I am new to transmission line theory. I am reading Microwave Engineering by David M. Pozar. He mentions:

"The key difference between circuit theory and transmission line theory is...
15. ## Thread: Rate of Return Analysis For Engineering Economics

by dzafar
Replies
3
Views
2,572

### Closed: Re: Rate of Return Analysis For Engineering Economics

Yes and also explain what they did so I can use it as a reference! Isn't that the point of this forum, to help?

Thanks
16. ## Thread: Rate of Return Analysis For Engineering Economics

by dzafar
Replies
3
Views
2,572

### Closed: Rate of Return Analysis For Engineering Economics

Hi there,

I am confused about rate of return analysis and cash flow diagrams.
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Any help would be appreciated.

Thanks!
17. ## Thread: Calculating Effective Annual Interest Rate from Nominal Interest Ratte

by dzafar
Replies
4
Views
3,409

### Closed: Calculating Effective Annual Interest Rate from Nominal Interest Ratte

Hi,

I am taking an engineering economics course. The questions says:

Suppose I have an effective interest rate – 10% per month,
compounded monthly, say – and I want to transform it
to an...
18. ## Thread: Parameterization when converting from cartesian, cylindrical or spherical

by dzafar
Replies
0
Views
4,574

### Closed: Parameterization when converting from cartesian, cylindrical or spherical

Hello there,

I am very very confused when it comes to 'parameterizing'. I do understand the physics part of the problems but getting started on my own is nearly impossible. I am attaching some...
19. ## Thread: Curent Density inside perfect conductors

by dzafar
Replies
3
Views
1,376

### Closed: Re: Curent Density inside perfect conductors

So you mean in the case I provided, J will have a random value? I am just concerned about this specific case when J = ∞.0!

Thanks
20. ## Thread: Curent Density inside perfect conductors

by dzafar
Replies
3
Views
1,376

### Closed: Curent Density inside perfect conductors

Hi there,

I understand that conductivity σ, inside a perfect conductor approaches ∞. Also, E-field, inside as well as on the surface of PEC is 0.

Then according to Ohm's Law: J = σE what should...
21. ## Thread: MATLAB 2D Graph of Total Charge vs. Voltage

by dzafar
Replies
1
Views
820

### Closed: MATLAB 2D Graph of Total Charge vs. Voltage

Hello,

I am new to MATLAB. I am trying to plot a 2D graph showing total charge (in pC) vs. Voltage (in V) ranging from 1 to 10V. Below is my attempt which gives an empty window.

q_tot =...
22. ## Thread: Conversion from Cartesian to Cylindrical Coordinate System

by dzafar
Replies
9
Views
2,361

### Closed: Re: Conversion from Cartesian to Cylindrical Coordinate System

Dear FootTea,

Thank you for your reply. I understand that because x, y, z are not constants we can not just use them directly. However, I am still having a hard time in understanding the...
23. ## Thread: Conversion from Cartesian to Cylindrical Coordinate System

by dzafar
Replies
9
Views
2,361

### Closed: Conversion from Cartesian to Cylindrical Coordinate System

Hello there,

I was solving problem 1.14 in Schaum's Outlines Electromagnetics (2nd Edition).

The problem states to convert a vector A from Cartesian to Cylindrical coordinates. I am attaching...
24. ## Thread: Critical path of combinational circuit

by dzafar
Replies
12
Views
2,809

### Closed: Re: Critical path of combinational circuit

@TrickyDicky,

In the image I attached last time, the path delay is 5ns (say each gate has a delay of 1 ns and and all inputs are sent at time 0). What I am confused about is that the 5ns delay can...
25. ## Thread: Processes and concurrent signal assignments

by dzafar
Replies
2
Views
727

### [SOLVED]Closed: Processes and concurrent signal assignments

Hello there,

I have a question regarding ARCHITECTURES in VHDL.

1. Can processes be used along with concurrent signal assignments under the same architecture?
I think yes, please let me know...
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