Question 220Electricity & Electronics - Assistant Engineer

The correct answer is C) The sound-powered telephone circuitry consists of a common-talk circuit and a selective-ringing circuit. This is correct because in a sound-powered telephone system, the talk circuit is typically a common circuit shared by multiple stations, while the ringing circuit is selective, allowing each station to be called individually. The common-talk circuit allows any station to communicate with any other station, while the selective-ringing circuit enables the system to direct the ringing signal to a specific station. The other options are incorrect because they do not accurately describe the configuration of a sound-powered telephone system. Option A refers to selective circuits for both talk and ringing, which is not the standard configuration. Option B and D describe combinations of circuit types that do not match the typical sound-powered telephone system design.