Electrical Machines Which of the following represents the commutator pitch? Number of conductors spanned by one coil at the back end of the armature. Number of conductors spanned by one coil at the front end of the armature. Number of commutator segments between two successive coils. The distance between the staring of first coil and its next successive coil Number of conductors spanned by one coil at the back end of the armature. Number of conductors spanned by one coil at the front end of the armature. Number of commutator segments between two successive coils. The distance between the staring of first coil and its next successive coil ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a single phase transformer the magnitude of leakage reactance is twice that of resistance of both primary and secondary. With secondary short circuited, the input power factor is 1/√5 1/√2 2/√5 1/3 1/√5 1/√2 2/√5 1/3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An 8 pole DC generator has 500 armature conductors and useful flux per pole of 0.065 Wb. What will be the emf generated if it is lap connected and runs at 1000 rpm. What must be the speed at which it is driven to produce the same emf if it is wave wound? 541.67V, 200 rpm. 2166.67V, 270 rpm. 541.67V, 250 rpm. 2166.67V, 230 rpm. 541.67V, 200 rpm. 2166.67V, 270 rpm. 541.67V, 250 rpm. 2166.67V, 230 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Alternator operates on the principle of self or mutual induction. mutual induction. electromagnetic induction. self induction. self or mutual induction. mutual induction. electromagnetic induction. self induction. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt machine generates 250 V on open circuit at 1000 RPM. Armature resistance is 0.5 Ω, field resistance 250 Ω. When running as a motor takes 4 A at 250 V. Calculate the efficiency when running as a motor taking 40 A at 250 V. Armature reaction weakens the field by 4%. 82.5% 72.5% 78.5% 67.5% 82.5% 72.5% 78.5% 67.5% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The oscillation in a synchronous motor can be damped out by running the motor on leading power factors. providing damper bars in the rotor pole faces. maintaining constant excitation. oscillation cannot be damped. running the motor on leading power factors. providing damper bars in the rotor pole faces. maintaining constant excitation. oscillation cannot be damped. ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS