🔍 Key Concepts

• Torque in a DC motor depends on the interaction between the field and armature magnetic fields • For a DC motor, the direction of rotation is determined by the relative polarity between the field and armature, not just one by itself • What happens to rotation if you reverse both field and armature currents at the same time vs. only one of them

💭 Think About

• Ask yourself: In a simple DC motor, if you keep the field the same and only reverse the armature current, what happens to the direction of torque? • Now ask: If you keep the armature the same and only reverse the field current, does the torque direction change or stay the same? • Finally, consider: If you reverse BOTH the field and armature currents at the same time, is the relative relationship between them changed or unchanged?

✅ Before You Answer

• Be clear on what determines direction of torque: it depends on the interaction (cross-product) of field and armature currents • Think about what happens to the magnetic polarity of the rotor (armature) vs. the stator (field) when only one is reversed • Verify which option(s), if any, claim that there is only one possible method versus more than one way to reverse rotation