My Report

Electrical Machines Practice Test 1


Correct Answer: 2 points | Wrong: -1 point
Grades: A* (100% score) | A (80%-99%) | B (60%-80%) | C (40%-60%) | D (0%-40%)
advertisement

1. For a reluctance motor, the maximum average torque occurs when δ = __________

2. If the salient pole rotor in a single phase reluctance motor is replaced by a cylindrical rotor, then Which of the following statements are true?

(i) reluctance offered to stator flux remains constant for all rotor positions
(ii) no reluctance torque will be developed
(iii) reluctance torque will be developed
(iv) reluctance offered to stator flux changes for all rotor positions

3. The area of two parallel plates is doubled and the distance between these plates is also doubled. The capacitor voltage is kept constant. Under these conditions, force between the plates of this capacitor __________

4. When a current of 5A flows through a coil of linear magnetic circuit, it has flux linkages of 2.4 wb-turns. What is the energy stored in the magnetic field of this coil in Joules?

5. Electromagnetic torque in rotating electrical machinery is present when ________

6. Which of the following equation best represents the mutual inductance between stator and rotor in a single phase cylindrical rotor synchronous machine? (where θr= space angle between stator and rotor field axis)

7. A parallel plate capacitor is charged and then the DC supply is disconnected. The plate separation is then increased. Between the plates which of the following statements are correct?

(i) electric field intensity is unchanged
(ii) flux density decreases
(iii) potential difference decreases
(iv) energy stored increases

8. Single phase reluctance motors are extensively used in ________

9. All practical electromechanical energy conversion devices make use of the magnetic field rather than the electric field as the coupling medium. This is because ________

10. Field winding carries which of the following current?


 

Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

Subscribe to his free Masterclasses at Youtube & discussions at Telegram SanfoundryClasses.