Question

The armature of a dc motor has 20 $\Omega$ resistance. It draws a current of 1.5 A when run by a 220 V dc supply. The value of the back emf induced in it is

• A. 150 V
• B. 170 V
• C. 180 V
• D. 190 V

Answer 1

Answer: (D)

190 V

back emf =$220-I\times R$= $220-1.5\times 20=190V$