Electrical Machines A 4 pole DC generator runs at 750 rpm and generate an emf of 240 V. The armature is wave wound and has 792 conductors. If the total flux from each pole is 0.0145 Wb. What is the leakage co-efficient? 1.4. 1.2. 1.5. 1.8. 1.4. 1.2. 1.5. 1.8. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements about commutating poles which are fitted on most large dc Shunt motors: 1. The commutating poles are placed in the geometric neutral plane and their number is usually Equal to the number of main poles 2. The winding on the commutating poles is connected in series with the shunt-field winding on the main poles 3. The polarity of the commutating pole must be that of the next pole further ahead 4. The commutating poles neutralize the reactance voltage produced in the coil undergoing Commutation. Of these statements, 2, 3 and 4 are correct 1, 2 and 4 are correct 1 and 4 are correct 1, 2 and 3 are correct 2, 3 and 4 are correct 1, 2 and 4 are correct 1 and 4 are correct 1, 2 and 3 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the magnetization characteristics of a dc generator : 1. It represents the variation of field flux with field current. 2. Variation of open-circuit terminal voltage with field current is independent of speed 3. It is non-linear from zero to rated field current 4. It helps to determine the critical field resistance at a given speed 5. It always starts from the origin Which of these statements are correct ? 1, 2 and 5 2, 3 and 4 3 and 5 1 and 4 1, 2 and 5 2, 3 and 4 3 and 5 1 and 4 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An electric motor with constant output power will have a torque speed characteristics in the form of a Rectangular hyperbola Straight line parallel to the speed axis. Circle about the origin. Straight line through the origin. Rectangular hyperbola Straight line parallel to the speed axis. Circle about the origin. Straight line through the origin. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A voltmeter gives 120 oscillations per minute when connected to the rotor of an induction motor. The frequency is 50Hz. The slip of the motor is 5% 25% 4% 2% 5% 25% 4% 2% ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Regenerative braking is possible in DC compound motor. DC series motor. DC shunt motor with field weakening control. DC shunt motor with armature resistance control. DC compound motor. DC series motor. DC shunt motor with field weakening control. DC shunt motor with armature resistance control. ANSWER DOWNLOAD EXAMIANS APP