Electrical Machines A 240 V dc series motor takes 40 A when giving its rated output at 1500 rpm. Its resistance is 0.3 Ω. The value of resistance which must be added to obtain rated torque at 1000 rpm is 6 Ω 1.9 Ω 5.7 Ω 2.2 Ω 6 Ω 1.9 Ω 5.7 Ω 2.2 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If Ke is eddy current constant, Kf is form factor, f is supply frequency, Bm maximum flux density in core of transformer, the expression of eddy current loss in transformer, is given by Kef2Kf2Bm. Kef2KfBm2. Kef2Kf2Bm2. KefKf2Bm2. Kef2Kf2Bm. Kef2KfBm2. Kef2Kf2Bm2. KefKf2Bm2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Larger values of air flux density is taken while designing IM for larger bore diameter. larger output. none. both. larger bore diameter. larger output. none. both. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The wound rotor type IM is used for____________ speed operation. minimum. variable. constant. maximum. minimum. variable. constant. maximum. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Slot wedges in a dc machine is made up of silicon steel. cast iron. fibre. mild steel. silicon steel. cast iron. fibre. mild steel. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When R2 is rotor resistance, X2 the rotor reactance at supply frequency and s the slip, then the condition for maximum torque under running condition will be R2 = s2X2. sR2 = X2. R2 = s2X2. R2 = sX2. R2 = s2X2. sR2 = X2. R2 = s2X2. R2 = sX2. ANSWER DOWNLOAD EXAMIANS APP