Which of the following components is essential for effective speed control in a multispeed motor?

In a multispeed motor, having a tapped field winding is crucial for effective speed control. This component allows the motor to adjust its speed by providing different voltage levels or current paths to the motor windings, enabling it to operate at various speeds without the need for complex additional hardware. The tapped field winding alters the magnetic field strength and, consequently, the speed of the motor by changing the configuration of the windings.

The other components mentioned, while useful in different contexts, do not inherently provide the same level of speed control. A speed sensor can monitor the motor's speed but does not directly affect its performance. A gearbox may change the output speed of the motor but does not modify the motor's intrinsic speed characteristics. A flywheel can help with stability and smooth operation but does not contribute to altering the motor's speed directly. Thus, the tapped field winding stands out as the essential component for achieving effective speed control in a multispeed motor setup.