question_answer

The current-voltage graph for a given metallic conductor at two different temperature \[{{\text{T}}_{\text{1}}}\]and \[{{\text{T}}_{2}}\]are as shown in the figure. Then:            

A)  \[{{T}_{1}}<{{T}_{2}}\] 

B)  nothing can be said about \[{{T}_{1}}\]and \[{{T}_{2}}\]

C)  \[{{T}_{1}}={{T}_{2}}\]                 

D)  \[{{T}_{1}}>{{T}_{2}}\]

Correct Answer: A

Solution :

\[R\propto \]temperature for conductor                 \[\therefore \]  \[\frac{V}{I}=R\]                 At \[{{T}_{2}},R\]is greater than \[{{T}_{1}}\]                 Hence, \[{{T}_{2}}>{{T}_{1}}\]