Final answer:
Measuring resistance between all leads of a multispeed shaded pole motor is not necessary since not all leads are interconnected, unlike in series-wound DC motors where resistance and back emf are crucial for performance analysis.
Step-by-step explanation:
When measuring the leads of a multispeed shaded pole motor, there should not necessarily be measurable resistance between all of the leads. Some leads might be for different windings or speed controls, and not all leads are connected directly to each other. However, in a series-wound DC motor, you can measure resistance and back emf (electromotive force) to understand the motor's operation.
For instance, with a 120-V series-wound DC motor drawing 0.50 A at full speed and with an armature coil resistance of 10 ohms, the resistance of the field coils can be calculated by analyzing the circuit when the motor draws its initial current of 2.0 A.
Likewise, the back emf can be calculated using the voltage, current, and resistance when the motor operates at full speed or at different speeds. Knowledge of these electrical properties is crucial in understanding motor performance and preventing issues like excessive initial current draws.