Which type of machine will create AC power?

The correct answer is the motor alternator, which is designed specifically to convert mechanical energy into alternating current (AC) electrical energy. The motor alternator typically consists of a motor that drives an alternator. As the motor operates, it spins the rotor of the alternator, generating AC power through electromagnetic induction. This process is widely used in various applications, such as providing backup power or in automotive systems to generate electricity.

Other options may not necessarily produce AC power directly. A transformer-receiver primarily serves to transform electrical voltages, while an inverter power supply converts DC power to AC but not directly from a mechanical source. A motor generator, although capable of generating power, often converts mechanical energy into direct current (DC), which may then need to be converted to AC using another component. The unique role of the motor alternator in directly creating AC power from mechanical energy makes it the best choice in this context.