Question
The specific resistance of a conductor increases with
A.
increase in temperature
B.
increase in cross-sectional area
C.
decrease in length
D.
decrease in cross-sectional area
Answer :
increase in temperature
Solution :
The specific resistance (resistivity) of a metallic conductor nearly increases with increasing temperature as shown in figure. This is because, with the increase in temperature the ions of the conductors vibrate with greater amplitude and the collisions between electrons and ions become more frequent, over a small temperature range (upto $${100^ \circ }C$$ ). The resistivity of a metal can be represented approximately by the equation
$${\rho _t} = {\rho _0}\left( {1 + \alpha t} \right)$$
The factor $$\alpha $$ is called the temperature coefficient of resistivity.
The specific resistance (resistivity) of a metallic conductor nearly increases with increasing temperature as shown in figure. This is because, with the increase in temperature the ions of the conductors vibrate with greater amplitude and the collisions between electrons and ions become more frequent, over a small temperature range (upto $${100^ \circ }C$$ ). The resistivity of a metal can be represented approximately by the equation
$${\rho _t} = {\rho _0}\left( {1 + \alpha t} \right)$$
The factor $$\alpha $$ is called the temperature coefficient of resistivity.
