The following figures shows the V-I graph of two resistors X and Y.
(a) Which resistor has a higher resistance? Explain briefly.
(b) If X and Y are connected in series, in which region will the V-I graph of the combined resistor lie?
(c) If X and Y are connected in parallel, in which region will the V-I graph of the combined resistor lie?
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Answer:
(a) Resistor X has a higher resistance. This is because it has a higher gradient. Gradient of the graph is V/I. Since R = V/I, the gradient of the graph gives the resistance of the resistor. Thus, a higher gradient means a higher resistance (resistor X).
(b) The combined resistor would lie in region P. This is because the combined resistor will have a higher resistance than X or Y alone (in series). The graph should be of a higher gradient than resistor X, and thus it will lie in region P.
(c) The combined resistor would lie in region R. This is because the combined resistor will have a lowerer resistance than X or Y alone (in series). The graph should be of a lower gradient than resistor Y, and thus it will lie in region R.
