Question

The current voltage graph for a given metallic wire at two different
temperatures $ {{T}_{1}} $ and $ {{T}_{2}} $ are shown in given figure, which of the relation is correct form the following?

• A. $ {{T}_{2}}>{{T}_{1}} $
• B. $ {{T}_{1}}>{{T}_{2}} $
• C. $ {{T}_{1}}={{T}_{2}} $
• D. none of these

Answer 1

Answer: (D)

The slope of given I-V curve $ \frac{1}{V}=\frac{1}{R} $ i.e., slope $ \frac{1}{R} $ The slope of graph at temperature $ {{T}_{1}} $ is greater than that at temperature $ {{T}_{2}} $ so $ {{R}_{1}}<{{R}_{2}} $ Since resistance increases with rise of temperature hence, $ {{T}_{2}}>{{T}_{1}} $