Page 525 - Basic Electrical Engineering
P. 525
b. flux = MMF × reluctance
c.
d.
3. Relative permeability of air is
a. equal to 0
b. equal to 1
c. equal to ∞
d. around 2000.
4. A magnetic circuit is said to be saturated when an increase in the field intensity results in
a. decrease in flux density
b. proportional increase in flux density
c. very marginal increase in flux density
d. sudden increase in flux density.
5. Which of the following is applicable for magnetic circuits?
a. Thevenin’s Theorem
b. Maximum Power Transfer Theorem
c. Norton’s Theorem
d. Kirchhoff’s Laws.
6. Material used for making a permanent magnet should have
a. large hysteresis loop area
b. small hysteresis loop area
c. low coercieve force
d. low saturation flux density.
7. The value of permeability of iron may be taken as
a. unity
b. zero
c. infinity
d. as high as 2000.
8. Unit of reluctance of a magnetic circuit is
a. AT/Wb
b. Wb/AT
