Electrical Machines A smaller air gap in a polyphase induction motor helps to increase the starting torque. reduce the chance of crawling. reduce the magnetizing current. reduce the chance of cogging. increase the starting torque. reduce the chance of crawling. reduce the magnetizing current. reduce the chance of cogging. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Flux density under trailing pole tips in case of generator will increase either increase or decrease decrease None of these increase either increase or decrease decrease None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the load current and the flux of a DC motor are held constant and voltage applied across its armature is increased by 5%, the speed of the motor will reduce by 5 %. depend on other factors. increase by 5 %. remain unchanged. reduce by 5 %. depend on other factors. increase by 5 %. remain unchanged. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In V/f speed control of 3-phase induction motor, with increase in frequency, the slip at which maximum torque occurs decrease. None of these increase. either of these. decrease. None of these increase. either of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum allowable moisture content of power transformer insulating oil is generally taken as 20 ppm. 25 ppm. 35 ppm. 45 ppm. 20 ppm. 25 ppm. 35 ppm. 45 ppm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature mmf in a dc machine is 1. stationary with respect to field poles 2. stationary with respect to armature 3. rotating with respect to field poles 4. rotating with respect to armature From these, the correct answer is 1, 4 2, 4 1, 3 2, 3 1, 4 2, 4 1, 3 2, 3 ANSWER DOWNLOAD EXAMIANS APP