Question

From the graph between current I and voltage V shown in figure, identify the portion corresponding to negative resistance:

• A. DE
• B. CD
• C. BC
• D. AB

Answer 1

Answer: (B)

Key Idea: Negative resistance means the resistance which decreases when temperature or voltage increases. From Ohms law, resistance $R=\frac{\Delta V}{\Delta I}$ Resistance is said to be negative, if an increasing voltage or temperature, current decreases. In V-I graph, for portion CD of graph, the current decreases with increasing voltage. Thus, portion CD corresponds to negative resistance.