All Questions
7
questions
1
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2
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93
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Can we measure resistance of a diode using Ohm's law $V=IR$ for a specific value of voltage and current?
As a diode doesn't follow $V$ proportional to $I$, I was wondering if we can use Ohm's law to calculate its resistance for a specific set of voltage and current, as its resistance varies as per the ...
2
votes
2
answers
23k
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Why in a conductor increase in temperature makes the atoms vibrate but in a semiconductor the kinetic energy of the free electrons is increased?
When temperature is increased in case of a semiconductor the free electron gets more energy to cross the energy gap to the conduction band from the valence band.so now more electrons can go easily to ...
- 31
0
votes
1
answer
74
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Point resistance
The resistance of a given object is expressed through:
$$R=\rho\frac{l}{A}$$
I'm wondering if there is any quantity like resistance at a specific point. For example, $R$ for a copper wire with l=...
- 3
1
vote
3
answers
6k
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Are thermistors and filament bulbs ohmic?
Conductors are ohmic if they have a constant resistance given that the physical conditions, such as temperature, are constant.
A filament bulb and thermistor are considered to be non-ohmic because ...
- 1,307
1
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1
answer
66
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How can I create an ohmic contact with selenium?
I would like to be able to measure the electrical resistance of selenium past its melting point, but to do this I need to create an Ohmic contact between the selenium and my multi-meter. What metals ...
- 127
0
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0
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37
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How am I obtaining silicon with resistivity proportional to the number of conduction electrons?
The resistivity of silicon is given by
$$\large\rho=\rho_0e^{\Large{{\frac{E_g}{2k_BT}}}}$$
and the number of conduction electrons in a semiconductor conduction band is
$$\large n_{\text{...
- 4,607
2
votes
0
answers
176
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Van der pauw method for an isolated hole
Van der pauw method is a way to measure the resistivity of a material with arbitrary shape while it meets some specifications ( being homogeneous and ...).
One of the conditions is that the sample ...
- 322