Maintenance Technician Practice Test

In a simple DC motor, what is the effect of having more loops in the armature?

1. The more powerful is the induced magnetic field

2. The smoother is the motor operation

3. The safer is the motor

4. The longer the motor takes to start

The correct answer is: The more powerful is the induced magnetic field

Having more loops in the armature of a simple DC motor increases the strength of the induced magnetic field, which directly contributes to the torque produced by the motor. This is based on Faraday's law of electromagnetic induction, which states that the induced electromotive force (EMF) in any closed circuit is equal to the rate of change of the magnetic flux through the circuit. In a DC motor, as the number of loops (or turns) of wire increases, the amount of magnetic field interactions that the loops have with the magnetic field provided by the motor's stator also increases. This results in a higher induced EMF and, subsequently, a higher torque output, leading to more power being available for the motor's operation. While increased loops can also contribute to smoother operation due to a more uniform magnetic field, the primary effect lies in the enhancement of the magnetic field, which boosts the overall performance and efficiency of the motor. The other options do not significantly relate to the primary function of increasing loops in the armature, especially regarding the main electromagnetic principles at play in motor operation.