Which formula represents the total voltage in a series circuit?

• A. VT = IR1 + IR2
• B. VT = VR1 + VR2 + VR3
• C. VT = 1/(1/R1 + 1/R2)
• D. VT = IR1 = IR2

Answer: (B)

The total voltage in a series circuit is represented by the formula that sums the individual voltage drops across each component in the circuit. In a series circuit, the same current flows through all components, and each resistor or load will have its own voltage drop based on Ohm's Law, which states that voltage (V) equals the product of current (I) and resistance (R).

Therefore, the total voltage is the sum of the voltages across each component: ( VT = VR1 + VR2 + VR3 ). This reflects the principle that, in a series circuit, the source voltage is divided among all the components according to their resistance values.

Other formulas provided deal with different aspects of circuits or configurations. The first option relates to calculating total resistance multiplied by current, which is not applicable for finding total voltage specifically. The third option describes the formula for equivalent resistance in parallel circuits, which is irrelevant for series circuits. Lastly, the fourth option incorrectly suggests that the total voltage equals the voltage across one resistor equal to another, which does not capture the total voltage in a series circuit.

Thus, summing all the individual voltages in a series setup confirms that ( VT = VR1 + VR2 + VR3 ) is