Which of the following is NOT a common cause of faults in circuits?

A lack of current is typically not categorized as a direct cause of faults in circuits. While insufficient current flow can lead to unreliable circuit operation, it doesn't inherently signify a fault in the circuit itself. Instead, common solder connections or component interactions usually drive faults.

In contrast, excessive voltage can lead to stress and failure of circuit components, potentially creating immediate faults. Component failure indicates a loss of functionality or efficiency within the circuit, which is a common and clear type of fault. Physical damage, such as from environmental factors or impacts, can directly lead to circuit malfunctions or broken connections. Therefore, option B stands out as it describes a condition that may arise due to circuit issues rather than being a direct fault-creating factor.