Delmar DC motors section 31
What does an electric motor do? - correct answer ✔Turns electrical energy
into mechanical energy
What is torque? - correct answer ✔A pushing or pulling force. You can have
full torque at 0 RPM in a DC motor.
Constant speed motor - correct answer ✔A DC shunt motor is often referred
to as a Constant speed motor.
counterelectromotive force (CEMF) or back-EMF - correct answer ✔CEMF is
the result of voltage induced on the armeture by the magnetic field of the
poles that is opposite in polarity to the voltage applied to the armeture limiting
the current flow.
CEMF is proportional to what? - correct answer ✔-Number of turns of wire in
the armeture
-Strength of the poles magnetic field
-Speed of rotation
What the losses for a DC motor? - correct answer ✔1. I2R loss in the
armature windings.
2. windage loss.
3. bearing friction.
4. brush friction.
Speed regulation - correct answer ✔The amount the armeture speed is
reduced when load is added
What does an electric motor do? - correct answer ✔Turns electrical energy
into mechanical energy
What is torque? - correct answer ✔A pushing or pulling force. You can have
full torque at 0 RPM in a DC motor.
Constant speed motor - correct answer ✔A DC shunt motor is often referred
to as a Constant speed motor.
counterelectromotive force (CEMF) or back-EMF - correct answer ✔CEMF is
the result of voltage induced on the armeture by the magnetic field of the
poles that is opposite in polarity to the voltage applied to the armeture limiting
the current flow.
CEMF is proportional to what? - correct answer ✔-Number of turns of wire in
the armeture
-Strength of the poles magnetic field
-Speed of rotation
What the losses for a DC motor? - correct answer ✔1. I2R loss in the
armature windings.
2. windage loss.
3. bearing friction.
4. brush friction.
Speed regulation - correct answer ✔The amount the armeture speed is
reduced when load is added
