The specific resistance of a conductor increases with

Options

A. increases in temperature
B. increases in cross-sectional area
C. decreases in length
D. decreases in cross-sectional area

Answer

A

Explanation

The specific resistance (resistivity) of a metallic conductor nearly increases with increasing temperature as shown in figure. This is because, with the increases in temperature the ions of the conductor vibrate with greater amplitude, and the collision between electrons and ions become more frequent, over all small temperature range (up to `100^(@)C`) . the resistivity of a metal can be represented approximately by the equation
`rho_(t)=rho_(0)(1+alphat)`
The factor `alpha` is called the temperature cofficient of resistivity