A motor is designed to operate on 117 V and draws a current of
13.3 A when it first starts up. At its normal operating speed, the
motor draws a current of 1.92 A. Obtain (a) the resistance of the
armature coil, (b) the back emf developed at normal speed, and (c)
the current drawn by the motor at one-third normal speed.
at (1/3)rd of normal speed ,back emf is (1/3) of its maximum