The importance of Ohm's Law is that if you know the value two of the variables in the equation, you can then determine the third. If you know current and resistance, you can find voltage from V = I R . (6 分 ) For example, if the current I = 0.2A and the resistance R = 1000 ohms , then V=___________. if V = 110V and R = 22000 ohms , then I=___________. if V = 220V and I = 5A , then R=___________.