Practice Test: Question Set - 09
1. Indicate which of the following material does not retain magnetism permanently.
- (A) Soft iron
- (B) Stainless steel
- (C) Hardened steel
- (D) None of the above
2. The ratio of intensity of magnetization to the magnetization force is known as
- (A) Flux density
- (B) Susceptibility
- (C) Relative permeability
- (D) None of the above
3. Which of the following is not a unit of flux?
- (A) Maxwell
- (B) Tesla
- (C) Weber
- (D) All of the above
4. If a copper disc is rotated rapidly below a freely suspended magnetic needle, the magnetic needle shall start rotating with a velocity
- (A) Less than that of disc but in opposite
direction
- (B) Equal to that of disc and in the same
direction
- (C) Equal to that of disc and in the opposite
direction
- (D) Less than that of disc and in the same
direction
5. A permeable substance is one
- (A) Which is a good conductor
- (B) Which is a bad conductor
- (C) Which is a strong magnet
- (D) Through which the magnetic lines of force
can pass very easily
6. A certain amount of current flows through a ring-shaped coil with fixed number of turns. How does the magnetic induction B varies inside the coil if an iron core is threaded into coil without dimensional change of coil?
- (A) Decreases
- (B) Increases
- (C) Remains same
- (D) First increases and then decreases depending
on the depth of iron insertion
7. Temporary magnets are used in
- (A) Loudspeakers
- (B) Generators
- (C) Motors
- (D) All of the above
8. Ampere-turn is the unit of magneto-motive force (mmf).
- (A) True
- (B) False
9. Which of the following is expected to have the maximum permeability?
- (A) Brass
- (B) Copper
- (C) Zinc
- (D) Ebonite
10. The magnetic reluctance of a material
- (A) Decreases with increasing cross sectional
area of material
- (B) Increases with increasing cross-sectional area
of material
- (C) Does not vary with increasing cross-sectional
area of material
- (D) Any of the above
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