D.C. servomotors are used in

Purely D.C. control systems
Purely A
servomotors are used in A. Purely
None of the above

The correct answer is C. Both D.C. and AC. control systems.

D.C. servomotors are used in both D.C. and AC. control systems. They are typically used in applications where precise control is required, such as in robotics, machine tools, and CNC machines. D.C. servomotors are also used in some applications where high power is required, such as in elevators and cranes.

D.C. servomotors are typically powered by a D.C. power supply, which provides a constant voltage to the motor. The motor then converts this voltage into mechanical power, which is used to rotate the motor shaft. The speed and direction of the motor shaft can be controlled by adjusting the voltage applied to the motor.

D.C. servomotors are available in a variety of sizes and power ratings. The size of the motor is typically determined by the amount of torque that the motor needs to produce. The power rating of the motor is typically determined by the amount of power that the motor needs to consume.

D.C. servomotors are typically used in applications where precise control is required. They are also used in applications where high power is required.

A. Purely D.C. control systems are systems that use only D.C. power supplies and D.C. motors. These systems are typically used in applications where precise control is not required, such as in conveyor systems and fans.

B. Purely AC. control systems are systems that use only A.C. power supplies and A.C. motors. These systems are typically used in applications where high power is required, such as in elevators and cranes.

D. None of the above is not a correct answer.