The voltage is presented by the equation V = IR where V is voltage in V, I is current in amperes ad R is resistance in ohms. If a platinum wire has a resistance of 15 Ω and is connected across the terminals of a 3.0 V flashlight battery, the current can be solved through V= IR, 3.0 V = I (15 Ω), and the current is 0.2 A.