Manganin and constantan have a low temperature coefficient of resistivity which means thata)their resistance values change very little with temperatureb)their resistance values only change at low temperaturesc)their resistance values change greatly with temperatured)their resistance values do not change with temperatureCorrect answer is option 'A'. Can you explain this answer?

Question

Answer

Resistivity in manganin and constantan is approx. same with temperature change so A is the answer...

Answer

Obviously A cuz temperature has only less affect on its resistance and resistivity

Answer

Low Temperature Coefficient of Resistivity in Manganin and Constantan

Introduction:
Manganin and constantan are two alloys that are commonly used in electrical and electronic applications due to their low temperature coefficient of resistivity. This property means that their resistance values change very little with temperature. Let's explore this concept in more detail.

Temperature Coefficient of Resistivity:
The temperature coefficient of resistivity (TCR) is a measure of how much the resistance of a material changes with temperature. It is usually denoted by the symbol α and is defined as the fractional change in resistance per degree Celsius (or per Kelvin) of temperature change. Mathematically, TCR is given by the equation:

α = (1/R) * (ΔR/ΔT)

where α is the temperature coefficient of resistivity, R is the resistance of the material, ΔR is the change in resistance, and ΔT is the change in temperature.

Manganin:
Manganin is an alloy composed of copper, manganese, and nickel. It has a very low TCR, typically around 0.00001 per degree Celsius. This means that the resistance of manganin changes very little with temperature. Even when subjected to a wide range of temperatures, manganin maintains a stable resistance value. This property makes it suitable for applications where precise resistance values are required, such as in resistors and strain gauges.

Constantan:
Constantan is another alloy commonly used in electrical and electronic circuits. It is composed of copper and nickel and also has a low TCR, typically around 0.00001 per degree Celsius. Similar to manganin, constantan exhibits minimal changes in resistance with temperature variations. This characteristic allows constantan to maintain its resistance value over a wide temperature range.

Advantages of Low TCR:
The low temperature coefficient of resistivity in manganin and constantan offers several advantages in practical applications:

1. Stability: The resistance values of these alloys remain relatively constant with temperature changes, providing stability in electronic circuits.

2. Accuracy: The low TCR allows for accurate measurements and consistent performance in devices that rely on precise resistance values.

3. Compensation: Manganin and constantan can be used to compensate for the temperature-dependent variations in other components, helping to maintain the overall performance of the circuit.

4. Sensing: The stable resistance values of these alloys make them suitable for use in temperature and strain sensing applications, such as thermocouples and strain gauges.

Conclusion:
In summary, manganin and constantan have a low temperature coefficient of resistivity, which means that their resistance values change very little with temperature. This property makes them ideal for applications where stable and accurate resistance values are required, ensuring the reliable performance of electrical and electronic circuits.

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