Draw resistivity rarr temperature (rho rarr T) graph for metals , alloys and semiconductor.

Draw resistivity rarr temperature (rho rarr T) graph for metals , allo

1.	Draw resistivity rarr temperature (rho rarr T) graph for metals , alloys and semiconductor.
Answer» Solution :`rArr` (a) For METALS relation between RESISTIVITY and temperature is given by,`rho_(T) = rho_(0)[1 + alpha (T- T_(0))]` hence, relation between `rho_(T)` and T will be straight line. `rArr` At temperature much lower than `0^(@)` C the graph will be different than straight line and will be as shown in figure below `rArr` At room temperature graph is a straight line. (b) Nichrome (alloy of nickel, iron, chromium) bas large resistivity and has weak dependence of resistivity with temperature. `rArr` Manganin and CONSTANTAN have similar properties (to resistivity less dependent on temperature) hence they are used in making standard (reference) wire bound resistors. `rArr`(c) Resistivity of semi conductor decreases with increase in temperature. For semiconductors `RHO rarr `T graph will be as shown below.

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Draw resistivity rarr temperature (rho rarr T) graph for metals , alloys and semiconductor.

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