Electrical Machines The supply voltage to an induction motor is reduced by 10%. By what percentage, approximately, will the maximum torque decrease? 19% 5% 40% 10% 19% 5% 40% 10% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines which of the following type of brush and their application is/are correct All of these copper graphite → low voltage high current density electro graphite → large ratings carbon brush → normal ratings All of these copper graphite → low voltage high current density electro graphite → large ratings carbon brush → normal ratings ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V DC series motor takes 40 A when giving its rated output at 1500 rpm. Its resistance is 0.3 ohms. The value of resistance which must be added to obtain rated torque at 1000 rpm is 1.9 ohms. 5.7 ohms. 6 ohms. 2.2 ohms. 1.9 ohms. 5.7 ohms. 6 ohms. 2.2 ohms. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the highest possible speed of turbo alternators? 4000 rpm 1500 rpm 3000 rpm 1000 rpm 4000 rpm 1500 rpm 3000 rpm 1000 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A self-excited shunt generator fails to build up, because 1. the field circuit is open 2. The armature circuit is open 3. the residual magnetism is absent 4. The direction of rotation is wrong From these, the correct answer is 1, 3 1, 2, 3 and 4 3 only 1, 2 and 3 1, 3 1, 2, 3 and 4 3 only 1, 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Cogging of induction motor occurs at low voltage and when stator and rotor poles are equal. high voltage and when stator and rotor poles are equal. low voltage and when stator and rotor poles are not equal. high voltage and when stator and rotor poles are not equal. low voltage and when stator and rotor poles are equal. high voltage and when stator and rotor poles are equal. low voltage and when stator and rotor poles are not equal. high voltage and when stator and rotor poles are not equal. ANSWER DOWNLOAD EXAMIANS APP
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