Electrical Machines A shunt generator has a critical field resistance of 300 Ω at a speed of 800 rpm if the speed is raised to 1000 rpm the critical field resistance is 150 Ω. 225 Ω. 375 Ω. 145 Ω. 150 Ω. 225 Ω. 375 Ω. 145 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC machine, for the same value of Æ, Z and N; which one of the following statements is correct? Armature emf is more with wave winding than with lap winding. Armature emf is same as long as the flux density in the air gap remains the same. Armature emf depends on weather the machine is running as a motor or generator. Armature emf is less with wave winding than with lap winding. Armature emf is more with wave winding than with lap winding. Armature emf is same as long as the flux density in the air gap remains the same. Armature emf depends on weather the machine is running as a motor or generator. Armature emf is less with wave winding than with lap winding. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For small value armature current Ia the torque developed by a DC series motor is proportional to √Ia. Ia. 1/Ia. Ia2. √Ia. Ia. 1/Ia. Ia2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of generated emf in the armature coil of a DC machine is 1. the same as that of the current in a generator 2. the same as that of the current in a motor 3. opposite to that of the current in a generator 4. opposite to that of the current in a motor From these, the correct answer is 2, 4 1, 3 1, 4 2, 3 2, 4 1, 3 1, 4 2, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a three phase star - delta transformer, what is the angle difference between primary and secondary phase voltages? Delta side leads by 30°. Delta side lags by -30°. Star side lags by -30°. Star side leads by 30°. Delta side leads by 30°. Delta side lags by -30°. Star side lags by -30°. Star side leads by 30°. ANSWER DOWNLOAD EXAMIANS APP
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 and P/2 V/2, I/2 and P/4 V, I and P V, I/2 and P/2 V/2, I and P/2 V/2, I/2 and P/4 V, I and P V, I/2 and P/2 ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS