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What are the requisite for making standard resistors? |
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Answer» tan , also known as Eureka, is an alloy of copper and NICKEL , was discovered in 1887 , and has been used for resistance all along, APART from other applications.Its preference for resistance wire stems from high resistivity, low temperature coefficient of resistance, ability to attain GOOD resistance values in small size, stability, ability to draw in thin wires. It's melting point is also high at over 1200 degrees Celsius.Apart from resistance, constantan is also used in thermocouples.Manganin is an improvement over constantan, discovered in 1892. It is an alloy of copper , manganese and nickel. Its temperature coefficient of resistance is near zero, and this makes it ideal for ammeter shunt, and high precision resistance.Manganin is used in resistance standards, its melting point is around 1000 degrees Celsius, and maximum usage temperature is limited to 300 degrees Celsius. |
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