MCQ of Basic Electrical page-4
31. Property of a material which opposes the production of magnetic flux in it is called
32. Unit of mmf is
33. Conductance is analogous to
34. An air gap is usually inserted in magnetic circuits to
35. Permeability is reciprocal of
b) Increase in mmf.
c) Increase in flux.
d) Increase in inductance.
36. The magnetic reluctance of a magnetic circuit decreases with
37. 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
a) Decrease in cross-sectional area.
Increase in cross-sectional area.
c) Increase in length of the magnetic path.
d) Decrease in relative permeability of the magnetic material of the circuit.
38. The ratio of total flux (flux in the iron path) to useful flux (flux in the air gap) is called
c) remain unaffected
39. According to Faraday’s law of electromagnetic induction, an emf is induced in a conductor whenever it
a) utilization factor
b) fringing factor
d) depreciation factor
40. “In all cases of electromagnetic induction, an induced voltage will cause a current to flow in a closed circuit in such a direction that the magnetic field which is caused by that current will oppose the change that produces the current”, is the original statement of
a) lies in a magnetic field.
b) Lies perpendicular to the magnetic field.
Cuts the magnetic flux.
d) Moves parallel to the direction of magnetic field.
b) Faraday’s law of magnetic induction.
c) Fleming’s law of induction.
d) Ampere’s law.
Multiple Choice Question (MCQ) of Materials page-6:51. The permeability and permittivity of a medium are
A) independent of each other
B) related by the atomic number
C) related by the Boltzmann’s constant
D) related by the velocity of electromagnetic waves.
Multiple Choice Question (MCQ) of Materials page-5:41. Bakelite is
A) highly inflammable
B) low resistance conductor
C) a semi-conductor
Multiple Choice Question (MCQ) of Materials page-4:31. Which of the following pairs is commonly used in thermocouples?
D) Silver-German silver.