Q123 / 180 · KCET 2018 · Physics
The I-V graphs for two different electrical appliances \( \mathrm{P} \) and \( \mathrm{Q} \) are shown in diagram . If \( R_{p} \) and
\( R_{Q} \) be the resistances of the devices, then
\( R_{Q} \) be the resistances of the devices, then
- A\( R_{p}=R_{Q} \)
- Correct answerB\( R_{p}>R_{Q} \)
- C\( R_{p} < R_{Q} \)
- D\( R_{p}=\frac{R_{Q}}{2} \)
Solution
By Ohm's law, \( V=I R \Rightarrow \frac{I}{V}=\frac{1}{R} \)
Thus, the slope of I-V graph is reciprocal of resistance. In the given diagram,
Slope of \( Q> \) Slope of \( P \)
\[ \begin{array}{l} \Rightarrow \frac{1}{R_{0}}>\frac{1}{R_{p}} \\ \Rightarrow R_{p}>R_{o} \end{array} \]
Thus, the slope of I-V graph is reciprocal of resistance. In the given diagram,
Slope of \( Q> \) Slope of \( P \)
\[ \begin{array}{l} \Rightarrow \frac{1}{R_{0}}>\frac{1}{R_{p}} \\ \Rightarrow R_{p}>R_{o} \end{array} \]
Hence, the correct answer is option: 'B'.