engineering recuitment CSPTCL JE Electrical Mock Test 2023 Electrical Machines DC Generators Types of DC Generators
A 220 V separately excited motor with Ra = 0.5 Ω running at 500 rpm draws a current of 20 A. The value of additional resistance in armature circuit to reduce the speed to 300 rpm at constant flux is
1
4.0 Ω
2
4.2 Ω
3
4.4 Ω
4
7.67 Ω