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 = sX2. R2 = s2X2. R2 = s2X2. sR2 = X2. R2 = sX2. R2 = s2X2. R2 = s2X2. sR2 = X2. 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 2.2 ohms. 5.7 ohms. 6 ohms. 1.9 ohms. 2.2 ohms. 5.7 ohms. 6 ohms. 1.9 ohms. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When operating, two or more transformers in parallel, % impedance of these transformers should be inversely proportional to MVA rating of transformers. proportionate to MVA rating of transformers. same. such that actual impedance of all transformers would be same. inversely proportional to MVA rating of transformers. proportionate to MVA rating of transformers. same. such that actual impedance of all transformers would be same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A lap wound 4 pole dc motor has 460 conductors. Find the number of parallel paths between the conductors? 2. 6. data provided is insufficient. 4. 2. 6. data provided is insufficient. 4. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the applied voltage of a certain transformer is increased by 50% and the frequency is reduced by 50%, the maximum flux density will (assuming that the magnetic circuit remains unsaturated) remain the same as the original changes to three times the original value changes to 1.5 times the original value changes to 0.5 times the original value remain the same as the original changes to three times the original value changes to 1.5 times the original value changes to 0.5 times the original value ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A synchronous generator is feeding a zero power factor (lagging) load at rated current. The armature reaction is cross – magnetizing. ineffective. magnetizing. demagnetizing. cross – magnetizing. ineffective. magnetizing. demagnetizing. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS