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This set of Electromagnetics Multiple Choice Questions & Answers (MCQs) focuses on Electromagnetics Set 13

Q1 | The minimum value of potential gradient in a cable occurs in
  • insulation
  • conductor
  • outer sheath
  • uniformly all over
Q2 | Acharge which when placed in vacuum from an equal and similar charge repels with aforce of 9 x 10 N, is known as
  • milli-coulomb
  • micro-coulomb
  • pico-coulomb
  • coulomb
Q3 | Dielectric strength of a medium is usually expressed in
  • j/mm
  • c/m2
  • kv/mm
  • n/mm
Q4 | A positive and a negative charge are initially 50 mm apart. When they are moved closetogether so that they are now only 10 mm apart, the force between them will be
  • 5 times smaller than before
  • 5 times greater than before
  • 10 times greater than before
  • 25 times larger than before
Q5 | Which is the most superior dielectric out of the following ?
  • air
  • glass
  • bakelite
  • paper
Q6 | When a dielectric is placed in an electric field the field strength
  • decreases
  • increases
  • reduces to zero
  • remain unchanged
Q7 | To prevent the generation of static charges on rubber or flat leather
  • surface is moistened
  • conductive dressing is done
  • oil compound dressing is done
  • talcum powder is sprayed on the surface
Q8 | Which of the following capacitor is preferred in case of single phase motor ?
  • mica capacitor
  • paper capacitor
  • electrolytic capacitor
  • ceramic capacitor
Q9 | A capacitance is a circuit component that opposes the change in circuit
  • current
  • voltage
  • impedance
  • none of the above
Q10 | A condenser suitable for D.C. only is
  • metallic plate variable gang condenser
  • metallic paper capacitor
  • oil impregrated paper condenser
  • poled aluminium electrolytic condenser
Q11 | In a capacitor, the electric charge is stored in
  • metal plates
  • dielectric
  • dielectric as well as metal plates
  • none of the above
Q12 | Tesla is a unit of
  • field strength
  • inductance
  • flux density
  • flux
Q13 | The materials having low retentivity are suitable for making
  • weak magnets
  • temporary magnets
  • permanent magnets
  • none of the above
Q14 | A magnetic field exists around
  • iron
  • copper
  • aluminium
  • moving charges
Q15 | Ferrites are materials.
  • paramagnetic
  • diamagnetic
  • ferromagnetic
  • none of the above
Q16 | Air gap has eluctance as compared to iron or steel path
  • little
  • lower
  • higher
  • zero
Q17 | The direction of magnetic lines of force is
  • from south pole to north pole
  • from north pole to south pole
  • from one end of the magnet to another
  • none of the above
Q18 | Which of the following is a vector quantity ?
  • relative permeability
  • magnetic field intensity
  • flux density
  • magnetic potential
Q19 | The two conductors of a transmission line carry equal current I in opposite directions.The force on each conductor is
  • proportional to 7
  • proportional to x
  • proportional to distance between the conductors
  • inversely proportional to i
Q20 | A material which is slightly repelled by a magnetic field is known as
  • ferromagnetic material
  • diamagnetic material
  • paramag>etic material
  • conducting material
Q21 | When an iron piece is placed in a magnetic field
  • the magnetic lines of force will bend away from their usual paths in order to go away from the piece
  • the magnetic lines of force will bend away from their usual paths in order to pass through the piece
  • the magnetic field will not be affected
  • the iron piece will break
Q22 | Fleming's left hand rule is used to find
  • direction of magnetic field due to current carrying conductor
  • direction of flux in a solenoid
  • direction of force on a current car¬rying conductor in a magnetic field
  • polarity of a magnetic pole
Q23 | The ratio of intensity of magnetisation to the magnetisation force is known as
  • flux density
  • susceptibility
  • relative permeability
  • none of the above
Q24 | The left hand rule correlates to
  • current, induced e.m.f. and direc¬tion of force on a conductor
  • magnetic field, electric field and direction of force on a conductor
  • self induction, mutual induction and direction of force on a conductor
  • current, magnetic field and direc¬tion of force on a conductor
Q25 | The unit of relative permeability is
  • henry/metre
  • henry
  • henry/sq. m
  • it is dimensionless