MCQOPTIONS
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This section includes 5 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Machines knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
All practical electromechanical energy conversion devices make use of the magnetic field rather than the electric field as the coupling medium. This is because ________ |
| A. | electric field systems present insulation difficulties |
| B. | electric field systems have more dielectric loss than the magnetic loss, for the same power rating of the machine |
| C. | in electric field systems, for normal electric field strength, the stored energy density is high |
| D. | in magnetic field systems, for normal magnetic flux density, the stored energy density is high |
| Answer» E. | |
| 2. |
Electromagnetic torque in rotating electrical machinery is present when ________ |
| A. | stator winding alone carries current |
| B. | rotor winding alone carries current |
| C. | air gap is uniform |
| D. | both stator and rotor windings carry current |
| Answer» E. | |
| 3. |
Singly and doubly excited magnetic systems applications are respectively ________ |
| A. | loud speakers and tachometers |
| B. | synchronous motors and moving iron instruments |
| C. | DC shunt machines and solenoids |
| D. | reluctance motors and synchronous motors |
| Answer» E. | |
| 4. |
In a doubly excited magnetic system of salient pole type stator and rotor, the reluctance torque is present only when _____________ |
| A. | both stator and rotor currents are acting |
| B. | stator current is acting alone |
| C. | rotor current is acting alone |
| D. | any of the stator or rotor currents acting alone |
| Answer» E. | |
| 5. |
In a doubly excited magnetic systems, the magnetic torques and forces act in such a direction as to tend to ___________ |
| A. | decrease the field energy at constant currents |
| B. | decrease the field co-energy at constant currents |
| C. | increase the field energy at constant currents |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |