Resistance can be calculated by:

Resistance can be calculated by:

• A. V × I
• B. E / I
• C. I / E
• D. E × I

Answer: (B)

Ohm’s law is the guiding idea: V = I R, or rearranged, R = V / I. If voltage is labeled E, the same relation is R = E / I. So the division of voltage by current gives resistance. This is the best answer because it directly reflects how resistance is defined: how much voltage you need to push a given current through a component. For example, with 10 V and 2 A, R = 10 / 2 = 5 Ω. The other expressions don’t yield resistance: voltage times current equals power, not resistance; current divided by voltage gives 1/R (the conductance), and voltage times current again is power.

Ohm’s law is the guiding idea: V = I R, or rearranged, R = V / I. If voltage is labeled E, the same relation is R = E / I. So the division of voltage by current gives resistance.

This is the best answer because it directly reflects how resistance is defined: how much voltage you need to push a given current through a component. For example, with 10 V and 2 A, R = 10 / 2 = 5 Ω.

The other expressions don’t yield resistance: voltage times current equals power, not resistance; current divided by voltage gives 1/R (the conductance), and voltage times current again is power.