Electrical Machines Maximum allowable tan - delta (tanδ) of dielectric dispassion factor of power transformer insulating oil is generally taken as 1 at 90°C. 3 at 90°C. 2 at 90°C. 0.5 at 90°C. 1 at 90°C. 3 at 90°C. 2 at 90°C. 0.5 at 90°C. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The starting resistance of DC motor is generally 1000 ohms. Infinitely large. Low. around 500 ohms. 1000 ohms. Infinitely large. Low. around 500 ohms. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V, DC shunt motor is operating at a speed of 1440 rpm. The armature resistance is 1.0 Ω and armature current is 10 A. of the excitation of the machine is reduced by 10%, the extra resistance to be put in the armature circuit to maintain the same speed and torque will be 3.1 Ω 2 .1 Ω 1.79 Ω 1.8 9 Ω 3.1 Ω 2 .1 Ω 1.79 Ω 1.8 9 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The emf induced in a conductor rotating in a bipolar field is both of above. None of these AC. DC. both of above. None of these AC. DC. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the rotor of a 3 phase induction motor is blocked then the slip is 0.7. 0.3. 0.54. 1. 0.7. 0.3. 0.54. 1. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The 3 - Φ induction motor with rotor circuit open will run normally. not run. make noise. get over heated. run normally. not run. make noise. get over heated. ANSWER DOWNLOAD EXAMIANS APP