Electric Vehicles Final Exam Study Guide
/False - Answer-Power electronic for modern battery electric vehicles have efficiencies
less than 80%. (T/F?)
/.True - Answer-A disadvantage of a DC motor with brushes and mechanical
commutator (switch) is that the brushes wear out and need to be replaced. (T/F?)
/.False - Answer-Most modern electric cars use three phase variable reluctance motors.
(T/F?)
/.True - Answer-Modern three phase brushless Dc motors (synchronous AC motors)
have strong permanent magnets in the rotors (T/F?)
/.False - Answer-Modern three phase induction motors have strong permanent magnets
in the rotators. (T/F?)
/.True - Answer-The stators of modern three phase brushless DC motors and modern
induction motors can be very similar. (T/F?)
/.True - Answer-Modern three phase induction motors have "squirrel cage" rotors that
are made of a magnetic material (iron) and a good conductor (copper or aluminum).
(T/F?)
/.False - Answer-Most modern gasoline/electric hybrid cars use induction motors. (T/F?)
/.True - Answer-Some modern plug in battery electric cars use induction motors. (T/F?)
/.False - Answer-A modern three phase induction motor with a controller for an electric
car cannot produce torque at zero speed. (T/F?)
/.F = BIL - Answer-What is the equation for the force, F, in Newtons on a wire of length
L meters, running through a constant magnetic field of B Webbers/(square meter) with
the wire carrying a current, I amps.
/.E = BLV - Answer-What is the equation for the "back electromotive force (EMF)"
denoted by E, generated in a wire of length L, moving at a velocity V perpendicular to a
magnetic field of constant flux density B.
/.True - Answer-The torque produced by a brush-commutator DC motor having a
permanent magnet stator is proportional to the current I in the coil winding of the motor
rotor (some other types of motors have a similar torque-current relationship). (T/F?)
/.False - Answer-Most modern electric motors do not need a controller (electronics) to
limit the maximum current at zero speed. (T/F?)
/False - Answer-Power electronic for modern battery electric vehicles have efficiencies
less than 80%. (T/F?)
/.True - Answer-A disadvantage of a DC motor with brushes and mechanical
commutator (switch) is that the brushes wear out and need to be replaced. (T/F?)
/.False - Answer-Most modern electric cars use three phase variable reluctance motors.
(T/F?)
/.True - Answer-Modern three phase brushless Dc motors (synchronous AC motors)
have strong permanent magnets in the rotors (T/F?)
/.False - Answer-Modern three phase induction motors have strong permanent magnets
in the rotators. (T/F?)
/.True - Answer-The stators of modern three phase brushless DC motors and modern
induction motors can be very similar. (T/F?)
/.True - Answer-Modern three phase induction motors have "squirrel cage" rotors that
are made of a magnetic material (iron) and a good conductor (copper or aluminum).
(T/F?)
/.False - Answer-Most modern gasoline/electric hybrid cars use induction motors. (T/F?)
/.True - Answer-Some modern plug in battery electric cars use induction motors. (T/F?)
/.False - Answer-A modern three phase induction motor with a controller for an electric
car cannot produce torque at zero speed. (T/F?)
/.F = BIL - Answer-What is the equation for the force, F, in Newtons on a wire of length
L meters, running through a constant magnetic field of B Webbers/(square meter) with
the wire carrying a current, I amps.
/.E = BLV - Answer-What is the equation for the "back electromotive force (EMF)"
denoted by E, generated in a wire of length L, moving at a velocity V perpendicular to a
magnetic field of constant flux density B.
/.True - Answer-The torque produced by a brush-commutator DC motor having a
permanent magnet stator is proportional to the current I in the coil winding of the motor
rotor (some other types of motors have a similar torque-current relationship). (T/F?)
/.False - Answer-Most modern electric motors do not need a controller (electronics) to
limit the maximum current at zero speed. (T/F?)
