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 5.7 Ω 2.2 Ω 1.9 Ω 6 Ω 5.7 Ω 2.2 Ω 1.9 Ω 6 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The slight curvature at the lower end of the OCC of a self excited DC generator is due to high speed. residual flux. high field resistance. magnetic inertia. high speed. residual flux. high field resistance. magnetic inertia. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a loaded DC generator, if the brushes are given a shift from the interpolar axis in the direction of rotation, then the commutation will improve with rise in terminal voltage. improve with fall of terminal voltage. deteriorate with rise in terminal voltage. deteriorate with fall of terminal voltage. improve with rise in terminal voltage. improve with fall of terminal voltage. deteriorate with rise in terminal voltage. deteriorate with fall of terminal voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole dynamo with wave wound armature has 51 slots contains 20 conductors in each slot. If induced emf 357 Volts and speed is 8500 rpm, flux per pole will be 3.5 mWb. 1.2 mWb. 1.4 mWb. 2.7 mWb. 3.5 mWb. 1.2 mWb. 1.4 mWb. 2.7 mWb. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC generators brushes are used for collecting of voltage reduce eddy current loss convert ac armature current in to dc collecting of current without any sparkings collecting of voltage reduce eddy current loss convert ac armature current in to dc collecting of current without any sparkings ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In DC series motor the speed is ______________ proportional to the armature current. directly. none of these. inversely. has no relation. directly. none of these. inversely. has no relation. ANSWER DOWNLOAD EXAMIANS APP