Questions tagged [physics]
Physics is the natural science that involves the study of matter and its motion through space and time.
419 questions
-1 votes
1 answer
70 views
Voltage and Charge Concentration
Im a Computer Engineering undergrad student and would like to think I have a solid foundation of electromechanics, though would appreciate some insight on a few Ideas. Please let me know if this model ...
2 votes
9 answers
820 views
Physical explanation of an integrator's capacitor behavior
I understand how the circuit behaves mathematically. I understand mathematically that $$i_c = C \times \frac{d(-v_\text{out})}{dt}$$ What I have trouble understanding is what is happening physically ...
- 107
2 votes
4 answers
188 views
Why is mass mapped to inductance in the Mass–Spring–Damper ↔ RLC analogy?
In the Mass–Spring–Damper ↔ RLC Circuit analogies, mass is mapped with inductance. F=mdv/dt, V=LdI/dt From a cause–effect point of view, I find this confusing: In mechanics, a force causes ...
- 181
4 votes
4 answers
997 views
How do capacitors withstand internal electrostatic pressure?
I am a physicist by trade, so I am unfamiliar with the details of electrical component design. Charged surfaces generally have a pressure of $$\frac{F}{A} = \frac{\varepsilon_0 E^2}{2}$$ due to ...
- 179
3 votes
3 answers
109 views
When a JFET is in saturation, does the depletion region completely block the channel or mostly block the channel?
I'm trying to understand the physics of a JFET in saturation, but books are contradictory. Some say that the depletion regions meet, pinching off the channel, but this is not a barrier to the ...
- 3,207
1 vote
1 answer
85 views
Existence of a certain type of optoelectronic device that detects EM waves while allowing them to pass through?
Is there an electronic device that detects EM waves while allowing them to pass through? Kind of like a window that can detect a measure the qualities/quantities of a light ray but lets it pass ...
- 21
0 votes
1 answer
55 views
Problem related to semiconductors & E-k graph?
I had found this image in a book, and the graph shows the relationship of E-k. I had studied that E is proportional to k^2 , and k is proportional to the inverse of wavelength. My question is why the ...
0 votes
4 answers
176 views
Radio wave nature
Have I right released if in a conductor there is AC current with the frequency range of 3 Hz and 300 GHz, then this conductor will be radiate radio waves? The above range is taken from the book "...
- 363
4 votes
2 answers
519 views
Can a battery supply charge from one terminal and not the other?
When a battery is unconnected and we connect a large piece of metal, say the negative terminal, I understand that the piece of metal/wire should acquire the same absolute potential as the negative ...
0 votes
1 answer
159 views
How do you calculate the permeability inside a nonuniform solenoid?
So, I am doing an experiment that has me calculating the inductance of a solenoid. Long story short, I am trying to find the inductance using the device's physical dimensions (i.e., number of turns, ...
- 511
1 vote
2 answers
128 views
How to determine the new speed of a DC shunt generator after load increase?
I am working on a DC shunt generator problem, but my calculated new speed seems incorrect. I would appreciate any help in identifying my mistake. Given data: Terminal voltage: Vt=250V Shunt field ...
0 votes
1 answer
101 views
Behavior of neutral charges
I can't understand the answer to the following question I found in a Physics book in the "Electric forces and electric fields" chaper. Question: Three objects are brought closer to each ...
- 181
0 votes
2 answers
70 views
What does the function F=N J/cm2 mean in practical application?
I'm trying to understand a publication. That publication has the mention of a function that helps define how to apply laser pulses over a certain area of a material. What is ...
2 votes
1 answer
152 views
How can I calculate impedance and propagation constant of coupled rectangular waveguides?
I am working on a two-port rectangular waveguide structure. I designed two different waveguides: WG1 with width 𝑎 and height 𝑏, WG2 with the same width 𝑎 but a reduced height of 𝑏−2ℎ. I am ...
- 21
11 votes
10 answers
2k views
Physically/fundamentally/literally, why does a significant voltage not develop across a diode in forward bias?
I am asking for a fundamental and physical explanation of why, not formulas. Let's take an ideal diode. Let's say I have some voltage source not big enough to breakdown and destroy the diode, but much ...
- 461