For a metallic wire, the ratio `V/i` ( `V=` applied potential difference and `i=` current flowing ) is

Options

A. independent of temperature
B. increases as the temperature rises
C. decreases as the temperature rises
D. increases or decreases as the temperature rises depending upon the metal

Answer

B

Explanation

The resistance of metallic wire at temperature `t^(@)C` is given by
`R_(t)=R_(0)(1+alphat)`
Where `alpha` is coefficient of expansion.
Hence, resistance of wire increases on increasing the temperature. Also, from Ohm's law, ration of `V/i` is equal to R i.e `V/i=R`
Hence on increasing the temperature the ratio `V/i` increases.