All Questions
Tagged with dielectric electromagnetism
10
questions
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Ampere's Law with dielectric
I am asked to calculate the magnetic-field-strength and magnetic-flux-density for different regions inside a coaxial-cable. I found Ampere's Law for that, but it uses \$\mu_0\$ , and the coaxial-cable ...
2
votes
2
answers
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How do I calculate the capacitance of a capacitive touch or water sensor?
Sensors like capacitive touch or moisture sensors are simply two traces drawn on a PCB. For example, you may check the Grove soil moisture sensor. In these types of sensors, the capacitance increases ...
- 2,519
1
vote
1
answer
134
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PEC-backed dielectric material
For the paper named "Antenna Miniaturization and Bandwidth Enhancement Using a Reactive Impedance Substrate" the statement "PEC-backed dielectric material", so what is the meaning of this statement? ...
- 283
3
votes
5
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Confusion regarding effect of dielectrics on energy stored in a capacitor
If inserting a dielectric has the effect of reducing the magnitude of the electric field in a capacitor (holding all other variables constant), then why is the energy stored in a capacitor directly ...
- 61
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2
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Understanding surface and volume polarization charges
Can someone please give me an intuition of this formulae?
I am unable to visualize the formulae in equation 5.26.
Specific question - How does a dielectric when kept in an external electric field ...
2
votes
1
answer
320
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Unit of permitivity
In electromagnetism, permittivity or absolute permittivity is the measure of resistance that is encountered when forming an electric field in a medium.
In SI units, permittivity ε is measured in ...
- 175
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1
answer
211
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Adding Slab to a Capacitor
I was solving a question in an Electromagnetics book and need some help: two parallel plates were connected to a 100V battery. The battery was removed and then a slab of dielectric material was placed ...
- 105
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3
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214
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How to detect non magnetic material?
I want to design a paintball counter. I have a metallic or plastic tube through which a paint ball passes.
How can I detect that the ball passed? What kind of sensors do I need?
I cannot see the ...
- 507
2
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1
answer
4k
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How do internal capacitor stud finders work?
I don't understand how a non-magnetic object like wood can be detected using a stud finder.
For instance, stud finders find wood from the dielectric constant, but I don't understand the principle.
The ...
- 507
19
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4
answers
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How does the tester screwdriver work?
How does the tester screwdriver work? If I put the tester screwdriver inside the "hot wire" of an electrical socket, it lits up if I press my finger against the metal cap on top of the screwdriver. ...
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