A student investigates whether a metallic resistor obeys Ohm’s law.
PHYSICS · Multi-part · CBSE · Physics · Current Electricity · Current Electricity
Problem
A student investigates whether a metallic resistor obeys Ohm’s law.
(i) State the general shape you would expect for the graph between potential difference V applied across the resistor and the current I through it when the temperature of the resistor is kept constant.
(ii) Explain how information about the value of the resistance can be obtained from such a graph.
(iii) On a hotter day, the same experiment is repeated with the resistor starting at a higher temperature. Describe qualitatively how the new V–I graph would differ from the first one and give a reason for the difference.
(iv) From the appearance of any V–I graph, describe the criterion you would use to decide whether a conductor obeys Ohm’s law.