Which of the following is true for parallel circuits?

• A. Current is the same through all components
• B. Voltage is the same across all components
• C. Resistance is cumulative
• D. All components must function for the circuit to operate

Answer: (B)

In parallel circuits, the defining characteristic is that the voltage across all components is the same. This means that regardless of how many resistors or devices are connected in parallel, each one experiences the total circuit voltage as the same potential difference. This property arises because each component is directly connected to the voltage supply terminals, allowing them to operate independently of each other.

The significance of this is that it allows multiple devices to function without affecting the voltage across one another, which is particularly useful in applications where devices need to run at a consistent voltage. Additionally, the total current in the circuit is divided among the different paths, so the sum of the currents through each branch equals the total current flowing from the source.

In contrast, while components in parallel do not require all of them to function for the circuit to operate, the current through each component varies depending on its resistance. Resistance in a parallel circuit is not cumulative in the same way it is in series circuits; instead, it is calculated using the formula for parallel resistance, which results in an overall lower resistance than any individual branch.