Question

calculate the voltage across 10 ohm​

Answer 1

Ohm's Law says that the current I = V / R. The voltage across the whole circuit is 12 volts, and the total resistance is 10 ohms. The answer is I = 12 / 10 = 1.2 amperes.

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With basic algebra, we can change Ohm's Law to solve for voltage instead of current:

I = V / R

IR = VR / R

IR = V.

V = IR.