Physics

Physics

Problem

The V–I graphs for two resistors P and Q are straight lines through the origin. The line for P makes an angle of 30∘30^{\circ} with the current axis (I-axis), while that for Q makes an angle of 60∘60^{\circ} with the same axis. Determine the ratio of their resistances RP:RQR_{P} : R_{Q}.
Intuitive explanation

The key is recognizing that resistance appears as the slope of a V–I graph: R=V/IR = V/I. Since both lines pass through the origin, the angle each line makes with the I-axis directly determines that slope—a steeper angle means a larger resistance. Use trigonometry to find each slope, then compare them to get the ratio.

Intuitive explanation

The key is recognizing that resistance appears as the slope of a V–I graph: R=V/IR = V/I. Since both lines pass through the origin, the angle each line makes with the I-axis directly determines that slope—a steeper angle means a larger resistance. Use trigonometry to find each slope, then compare them to get the ratio.

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