NEET-XII-Physics
32: Electric Current in Conductors
- #5As the temperature of a conductor increases, its resistivity and conductivity change. The ratio of resistivity to conductivity
(a) increases
(b) decreases
(c) remains constant
(d) may increase or decrease, depending on the actual temperaturedigAnsr: aAns : (a) increases
Resistivity (ρ) of a conductor is the reciprocal of the its conductivity(σ). Thus,
`` \rho =\frac{1}{\sigma }``
The ratio of the resistivity and the conductivity,
`` \frac{\rho }{\sigma }=\frac{\rho }{1/\rho }={\rho }^{2}``
As resistivity increases with temperature, the square of resistivity will also increase. Hence, the ratio of resistivity and conductivity will increase with increase in temperature.
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