What is the formula for calculating Thevenin or Norton equivalent resistance?

What is the formula for calculating Thevenin or Norton equivalent resistance?

• A. V(short circuit)/I(open circuit)
• B. V(open circuit)/I(short circuit)
• C. I(open circuit)/V(short circuit)
• D. I(short circuit)/V(open circuit)

Answer: (B)

The formula for calculating Thevenin or Norton equivalent resistance is derived from measuring the voltage and current at specific conditions of the circuit. The correct formula is the open circuit voltage (V) divided by the short circuit current (I). In an open circuit condition, the voltage measured across the terminals of interest is the Thevenin voltage, which is the voltage when no current is flowing through the load. On the other hand, the short circuit condition involves connecting the terminals with a wire, allowing maximum current to flow through the circuit. The current measured in this scenario is the short circuit current, which directly relates to the equivalent resistance. The relationship shows that the equivalent resistance can be obtained by taking the open circuit voltage and dividing it by the short circuit current. This forms a direct relationship whereby knowing how much voltage is present when no current flows allows one to determine how much current would flow if that voltage were applied to a short circuit, thus indicating the total resistance in the circuit. Therefore, the formulation of V(open circuit)/I(short circuit) provides a clear and effective method for evaluating Thevenin or Norton equivalents in circuit analysis.

The formula for calculating Thevenin or Norton equivalent resistance is derived from measuring the voltage and current at specific conditions of the circuit. The correct formula is the open circuit voltage (V) divided by the short circuit current (I).

In an open circuit condition, the voltage measured across the terminals of interest is the Thevenin voltage, which is the voltage when no current is flowing through the load. On the other hand, the short circuit condition involves connecting the terminals with a wire, allowing maximum current to flow through the circuit. The current measured in this scenario is the short circuit current, which directly relates to the equivalent resistance.

The relationship shows that the equivalent resistance can be obtained by taking the open circuit voltage and dividing it by the short circuit current. This forms a direct relationship whereby knowing how much voltage is present when no current flows allows one to determine how much current would flow if that voltage were applied to a short circuit, thus indicating the total resistance in the circuit.

Therefore, the formulation of V(open circuit)/I(short circuit) provides a clear and effective method for evaluating Thevenin or Norton equivalents in circuit analysis.