Instructions

• 1). Recall the properties of resistors in parallel circuits. Because they are connected to the same two points, they each have the same voltage, but the current is divided between them.
  
  
• 2). Study Ohm's Law. Ohm's Law is is V = IR, where V is the voltage, I the current and R the resistance.
  
  
• 3). Use Ohm's Law to add parallel resistors. The equation is 1/R(Total) = 1/R1 + 1/R2 + 1/R3 + ...+ 1/R(Last).
  
  
• 4). Apply Step 3 to calculate the total resistance of two resistors placed parallel to each other. The equation is 1/R(Total) = 1/R1 + 1/R2. Use R1 = R2 = 4 ohms. This gives 1/R(Total) = 1/4 ohms + 1/ 4 ohms. The result is 1/R(Total) = 0.25 ohms + 0.25 ohms = 0.5 ohms, and therefore R(Total) is 2 ohms.