QUIZ TEST


Welcome


You have to select only one out of 4


1. The magnetic reluctance of a magnetic circuit decreases with

Decrease in cross-sectional area
Increase in cross-sectional area
Increase in length of the magnetic path
Decrease in relative permeability of the magnetic material of the circuit

2. A ring-shaped coil with fixed number of turns of it carries a current of certain magnitude. If an iron core is threaded into the coil without any change in coil dimensions, the magnetic induction density will

Increase
Reduce
remain unaffected
unpredictable

3. The ratio of total flux (flux in the iron path) to useful flux (flux in the air gap) is called

utilization factor
fringing factor
leakage factor
depreciation factor

4. According to Faraday’s law of electromagnetic induction, an emf is induced in a conductor whenever it

lies in a magnetic field
Lies perpendicular to the magnetic field
Cuts the magnetic flux
Moves parallel to the direction of magnetic field

5. In Fleming’s left-hand rule thumb always represents direction of

Current flow
Induced emf
Magnetic field
Mechanical force

6. If a current carrying conductor is placed in a magnetic field, the mechanical force experienced on the conductor is determined by

Simple product
Dot product
Cross product
Any of these

7. The force experienced by a current carrying conductor lying parallel to a magnetic field is

Zero
B ? ?
B ? ? sin??
B ? ? cos??

8. The field at any point on the axis of a current carrying coil will be

Perpendicular to the axis.
Parallel to the axis.
At an angle of 45° with the axis.
Zero

9. The magnetic flux inside the exciting coil

Is the same as on its outer surface
Is zero
Is greater than that on its outside surface
Is lower than that on its outside surface

10. If the two conductors carry current in opposite directions there will be

A force of attraction between the two conductors
A force of repulsion between the two conductors
No force between them
None of these