Variation of Resistance with Temperature - NEET Physics Questions
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Variation of Resistance with Temperature

Practice Questions:
Question 1: difficult

Two wires of resistances R1 and R2 have temperature coefficient of resistances α1 and α2 respectively. These are joined in series. The effective temperature coefficient of resistance is :

1. \[\frac{\alpha_{1}+\alpha_{2}}{2}\]
2. \[\sqrt{\alpha_{1}\alpha_{2}}\]
3. \[\frac{\alpha_{1}R_{1}+\alpha_{2}R_{2}}{R_{1}+R_{2}}\]
4. \[\frac{\sqrt{R_{1}R_{2}\alpha_{1}\alpha_{2}}}{\sqrt{R_{1}^{2}R_{2}^{2}}}\]
View Answer

When two resistors with resistances

R1R_1

and

R2R_2

and temperature coefficients of resistance

α1\alpha_1

and

α2\alpha_2

are connected in series, the effective temperature coefficient of resistance

αeff\alpha_{\text{eff}}

is given by the formula:

 

αeff=α1R1+α2R2R1+R2\alpha_{\text{eff}} = \frac{\alpha_1 R_1 + \alpha_2 R_2}{R_1 + R_2}

 

This formula takes into account the individual resistances and temperature coefficients of the two wires, considering that their total resistance is the sum of the individual resistances.

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