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 temperature rises depending upon the metal

Answer

B

Explanation

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