Practice Test: Question Set - 01
1. Fleming's left hand rule is used to find
- (A) Direction of magnetic field due to current carrying
conductor
- (B) Direction of flux in a solenoid
- (C) Direction of force on a current carrying conductor
in a magnetic field
- (D) Polarity of a magnetic pole
2. A coil of wire is placed in a changing magnetic field. If the number of turns in the coil is decreased, the voltage induced across the coil will
- (A) Increase
- (B) Decrease
- (C) Remain
constant
- (D) Be
excessive
3. The force between two long parallel conductors is inversely proportional to
- (A) Radius of conductors
- (B) Current in one conductor
- (C) Product of current in two conductors
- (D) Distance between the conductors
4. What is the magneto-motive force in a 75-turn coil of wire when there are 4 A of current through it?
- (A) 18.75 At
- (B) 30 At
- (C) 300 At
- (D) 187 At
5. Substances which have permeability less than the permeability of free space are known as
- (A) Ferromagnetic
- (B) Paramagnetic
- (C) Diamagnetic
- (D) Bipolar
6. What is the magneto-motive force (mmf) of a wire with 8 turns carrying three amperes of current?
- (A) 2,400
At
- (B) 240 At
- (C) 24 At
- (D) 2.4 At
7. Which of the following is the unit of magnetic flux density?
- (A) Weber
- (B) Lumens
- (C) Tesla
- (D) None of the above
8. For a given wire-wound core, an increase in current through the coil
- (A) Reverses
the flux lines
- (B) Decreases
the flux density
- (C) Increases
the flux density
- (D) Causes
no change in flux density
9. When a magnet is in motion relative to a coil the induced e.m.f. does not depend upon
- (A) Resistance of the coil
- (B) Motion of the magnet
- (C) Number of turns of the coil
- (D) Pole strength of the magnet
10. If the steel disk in a crankshaft position sensor has stopped with the tab in the magnet's air gap, the induced voltage
- (A) Increases
- (B) Decreases
- (C) Is
zero
- (D) Will
remain constant
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