Electrical Machines A 4 pole lap wound dc generator has 4 brushes, if one of the brush is damaged, what will be the change in V, I and P ratings V/2, I/2 and P/4 V, I and P V/2, I and P/2 V, I/2 and P/2 V/2, I/2 and P/4 V, I and P V/2, I and P/2 V, I/2 and P/2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 2 pole synchronous machine is operating at 3000 rpm. Find the relation between electrical angular momentum (ωe) and mechanical angular momentum (ωm) ? ωe = 1/2*ωm ωe = 4*ωm ωe = ωm ωe = 2*ωm ωe = 1/2*ωm ωe = 4*ωm ωe = ωm ωe = 2*ωm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The brush-axis of a bipolar dc motor is rotated by 90°. The effect of this rotation on the back emf Eband the torque developed Tdwould be such that both Eb and Td are zero Eb is zero, but Td is unchanged both Eb and Td are unchanged Eb is unchanged, but Td is zero both Eb and Td are zero Eb is zero, but Td is unchanged both Eb and Td are unchanged Eb is unchanged, but Td is zero ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The synchronous motor can be started by coupling it with a DC compound motor. any of the above methods. providing damper winding in its rotor circuit. coupling it with a small AC induction motor called the pony motor. coupling it with a DC compound motor. any of the above methods. providing damper winding in its rotor circuit. coupling it with a small AC induction motor called the pony motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Dynamic braking is employed to brake non reversing drive reversing drive None of these both 1 and 2 non reversing drive reversing drive None of these both 1 and 2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The external resistance to be added in the armature circuit to limit the armature current to 125% of its rated value is 15.9 Ω 15.1 Ω 31.1 Ω 31.9 Ω 15.9 Ω 15.1 Ω 31.1 Ω 31.9 Ω ANSWER DOWNLOAD EXAMIANS APP