Sometimes a circuit must be opened in order to add or remove resistance.

Sometimes a circuit must be opened in order to add or remove resistance.

• A. True
• B. False
• C. Sometimes
• D. Never

Answer: (A)

When you need to change the resistance that a circuit presents, you often have to break the current path so you can place or remove a resistor in series or parallel. This means opening the circuit to physically connect or disconnect the component, and you typically do this with the power off to stay safe and avoid shorts. Because there are actual situations where you are swapping in or taking out a discrete resistor, the statement is true. Keep in mind there are ways to change effective resistance without swapping parts—such as using a potentiometer or a switch to vary the value—but adding or removing a resistor component itself requires opening the circuit.

When you need to change the resistance that a circuit presents, you often have to break the current path so you can place or remove a resistor in series or parallel. This means opening the circuit to physically connect or disconnect the component, and you typically do this with the power off to stay safe and avoid shorts. Because there are actual situations where you are swapping in or taking out a discrete resistor, the statement is true.

Keep in mind there are ways to change effective resistance without swapping parts—such as using a potentiometer or a switch to vary the value—but adding or removing a resistor component itself requires opening the circuit.