In circuit diagrams, which symbol represents a motor?

In circuit diagrams, the symbol for a motor is characterized by a specific design that often resembles a circle with a letter 'M' inside or may include additional lines representing the coil or windings of the motor. This symbol indicates the presence of a device that converts electrical energy into mechanical energy through the interaction of magnetic fields and electric current.

Motors are vital components in circuits intended to drive mechanical loads, such as fans, pumps, and other machinery. Recognizing this symbol is crucial for understanding and interpreting circuit diagrams, especially in practical applications where motors play an essential role in operation.

The other options represent different devices: the microphone typically has a symbol that signifies transduction of sound into electrical signals, the transformer is depicted with two coils to show the principle of electromagnetic induction, and the variable resistor symbol usually has a zigzag representation indicating its adjustability in resistance. Understanding the symbols for these devices helps in differentiating their functions within an electrical circuit.