MCQs of Principles of Electromechanical Energy Conversion (Electrical Machine - I - 3140913)

Electrical Machine - I (3140913) MCQs

MCQs of Principles of Electromechanical Energy Conversion

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An electromechanical energy conversion device is one which converts _______

(a)	Electrical energy to mechanical energy only
(b)	Mechanical energy to electrical energy only
(c)	All of the mentioned
(d)	None of the mentioned

What is the coupling field used between the electrical and mechanical systems in energy conversion devices?

(a)	Magnetic field
(b)	Electric field
(c)	Magnetic field or Electric field
(d)	None of the mentioned

The energy storing capacity of the magnetic field is about ________ times greater than that of the electric field.

(a)	50,000
(b)	25,000
(c)	10,000
(d)	40,000

The formula for energy stored in the mechanical system of linear motion type is ______

(a)	$\frac{1}{2} J ω^{2}$
(b)	$\frac{1}{2} m v^{2}$
(c)	$\frac{1}{2} C V^{2}$
(d)	$\frac{1}{2} L I^{2}$

In an electromechanical energy conversion device, the coupling field on the (i) electrical side is associated with emf and current (ii) electrical side is associated with torque and speed (iii) mechanical side is associated with emf and current (iv) mechanical side is associated with torque and speed From the above, the correct statements are

(a)	(i) & (ii)
(b)	(iii) & (iv)
(c)	(i) and (iv)
(d)	(ii) & (iii)

A coupling magnetic field must react with (i) electrical system in order to extract energy from mechanical system (ii) mechanical system in order to extract energy from mechanical system (iii) electrical system in order to extract energy from electrical system (iv) mechanical system in order to extract energy from electrical system (v) electrical or mechanical system for electro-mechanical energy conversion From the above, the correct statements are

(a)	(i), (ii) & (iii)
(b)	(ii), (iii) & (v)
(c)	(ii), (iii) & (iv)
(d)	(ii), (iii) & (v)

The developed electromagnetic force and/or torque in electromechanical energy conversion system acts in such a direction that tends to ___________

(a)	increase the stored energy at constant mmf
(b)	decrease the stored energy at constant mmf
(c)	decrease the co-energy at constant mmf
(d)	increase the stored energy at constant flux

The developed electromagnetic force and/or torque in electromechanical energy conversion systems, acts in a direction that tends to ___________ (i) increase the co-energy at constant flux (ii) increase the co-energy at constant mmf (iii) decrease the stored energy at constant mmf (iv) decrease the stored energy at constant flux Which of the above statements are correct?

(a)	(ii), (iv)
(b)	(i), (iii)
(c)	(ii), (iii)
(d)	(i), (iv)

A physical system of electromechanical energy conversion consists of a stationary part creating a magnetic field with electric energy input, and a moving part giving mechanical energy output. If the movable part is kept fixed, the entire electrical energy input will be _______

(a)	stored in the magnetic field
(b)	stored in the electric field
(c)	divided equally between the magnetic and electric fields
(d)	zero

10.

For a toroid to extract the energy from the supply system, the flux linkages of the magnetic field must be ________

(a)	zero
(b)	changing or varying
(c)	constant
(d)	any of the mentioned

Showing 1 to 10 out of 34 Questions