What is the effect of temperature on the resistance of a metallic conductor?
As temperature increases, the resistance of a metallic conductor generally increases.
How does resistance change with temperature in semiconductors?
In semiconductors, resistance decreases as temperature increases.
What is the temperature coefficient of resistance?
The temperature coefficient of resistance is a measure of how much a material's resistance changes with temperature.
Why does the resistance of metals increase with temperature?
Resistance in metals increases with temperature due to increased atomic vibrations, which cause more frequent scattering of electrons.
How does superconductivity relate to temperature?
Superconductivity occurs when a material's resistance drops to zero below a certain critical temperature.
What is the formula for determining resistance change with temperature?
ΔR = αR₀ΔT, where ΔR is the change in resistance, α is the temperature coefficient, R₀ is the original resistance, and ΔT is the change in temperature.
In which type of material does resistance decrease as temperature increases?
Resistance decreases with increasing temperature in semiconductors.
What does a negative temperature coefficient indicate?
A negative temperature coefficient indicates that resistance decreases with increasing temperature.
How does resistance affect power losses in electrical systems?
Increased resistance leads to higher power losses due to Joule heating (P = I²R).
What is an example of a device that uses temperature-dependent resistance?
Thermistors are devices that use temperature-dependent resistance to measure temperature changes.
How does temperature affect the resistivity of materials?
Temperature affects resistivity by increasing it in conductors and decreasing it in semiconductors.
What is meant by critical temperature in superconductors?
The critical temperature is the temperature below which a material becomes superconducting, having zero resistance.
Can temperature-corrected resistance be used to measure temperature?
Yes, changing resistance due to temperature can be calibrated to measure temperature in devices such as RTDs (Resistance Temperature Detectors).
Why are ceramic materials often used in temperature sensors?
Ceramic materials are used because they have predictable resistance changes with temperature and are stable over wide temperature ranges.
What is PTC in relation to thermistors?
PTC stands for Positive Temperature Coefficient, indicating resistance increases as temperature increases in these thermistors.