QUESTION 1 When discussing motors with commutators and brushes, the neutral plane is: O perpendicular to the magnetic field of the magnets, and alignment of the brushes should be along the neutral plane in order to minimize commutator sparking O the conductor that allows current to return back to the source. O the plane resulting in the maximum number of magnetic lines that will be cut when the motor is in rotation. O parallel to the magnetic field of the magnets, and alignment of the brushes should be perpendicular to the neutral plane in order to minimize commutator sparking

A 4 pole d.c. motor takes a 38.6 A armature current. The armature has lap connected 350 conductors. The flux per pole is 15 mWb. Calculate the gross torque developed by the armature of the motor. Also calculate Torque if flux per pole changes to 18 mWb and state difference in torque from 18 mWb to 15 mWb

A motor can have different torque characteristics depending on the resistance of the rotor bars and the inductive reactance of the rotor. With this in mind, which of the following is a true statement? A - The resultant flux density in the air gap between the rotor and the stator approaches zero as torque increases. B - As the motor speeds up, inductance is increased because slip and the frequency of the induced EMF is improved. C - The phase angle of the rotor affects the amount of induced current that flows in the rotor and the impedance between the rotor current and induced voltage. D - The impedance of the rotor affects the amount of induced current that flows in the rotor and the phase angle between the rotor current and induced voltage.