The conduction of electricity across the surface of a dielectric is called
creepage
skin effect
surface effect
crosstalk
Correct Answer :
A. creepage
Related Questions
Defined as the ratio of the volume occupied by the atoms or ions in a unit cell divided by the volume of the unit cell and is used to measure the compactness of a crystal.
Atomic packing factor (APF)
Ionic Packing Ratio (IPR)
Atomic compacting factor (ACF)
Ionic compacting ratio (ICR)
The resistivity of a conductor ___________ with an increase in temperature.
increases
decreases
remains the same
becomes zero
Which of the following electric quantities is vector in character?
Field
Charge
Energy
Potential Difference
If the number of valence electrons of an atom is more than 4a the substance is called
a semiconductor
a conductor
an insulator
a semi-insulator
The emission of electrons from hot bodies is called
Radiation effect
Edison effect
Skin effect
Half effect
What is the practical unit of electrical energy?
Watt
Kilowatt-hour
Kilowatt-second
Megawathour
The total number of magnetic lines of force in a magnetic field is called
Magnetic flux
Magnetic flux density
Magnetic flux intensity
Magnetic potential
What is the unit of magnetomotive force?
Volt
Tesla
Ampere- turn
Weber
The magnitude of the induced emf in a coil is directly proportional to the rate of change of flux linkages. This is known as
Joule's Law
Faraday's second law of electromagnetic induction
Faraday's first law of electromagnetic induction
Coulomb's Law
Which of the following is a vector quantity?
Magnetic potential
Magnetic field intensity
Magnetic permeability
F lux density
Gases whose particles are charged are known as
Conductors
Insulators
Gaseous Conductors
Plasma
A t/m is a unit of
Mmf
Emf
Reluctance
Magnetizing force
The flux density in an air-cored coil is 10^-3 Wb/m^2. With a cast iron core of relative permeability 100 inserteda the flux density will become
10^-3 Wb/m^2
10^-2 Wb/m^2
10^3 Wb/m^2
0.1 Wb/m^2
When the relative permeability of a material is slightly less than 1a it is called _____ material.
diamagnetic
ferromagnetic
paramagnetic
non-magnetic
What is the diameter of an atom?
About 10^-10 m
About 10^-10 cm
About 10^-10 mm
About 10^-10 �m
The permittivity of a material is given by one of the following formulas.
DE
E/D
D^2/E
D/E
If you hold the conductor with right hand so that the stretched thumb points in the direction of the currenta then encircling fingers will give the direction of magnetic lines of force round the conductor. This is known as
Left hand cork screw rule
Right hand cork screw rule
Left hand rule
Right hand rule
The reluctance of a magnetic circuit is not dependent on which of the following?
Number of turns of coil
Magnetomotive force
Flux density in the circuit
Current in the coil
Electric field intensity at a point is numerically equal to ________ at that point.
potential gradient
potential difference
dielectric constant
the force
The B-H curve for ________ is a straight line passing through the origin.
cobalt
air
hardened steel
soft iron
When a current carrying conductor is placed in a magnetic fielda the maximum force will act on the conductor when the conductor is at an angle of _______ to the magnetic field.
45o
60o
30o
90o
One electron volt (1 eV) is equivalent to _____ joules
1.3 x 10^-19
1.4 x 10^-19
1.5 x 10^-19
1.6 x 10^-19
Whenever a flux inking a coil or current changesa an emf is induced in it. This is known as
Joule's Law
Coulomb's Law
Faraday's first law of electromagnetic induction
Faraday's second law of electromagnetic induction
The force between two magnetic poles varies with the distance between them. The variation is ______ to the square of that distance.
Equal
Greater than
Directly proportional
Inversely proportional
How is mutual inductance between two coils decreased?
By using a common core
By moving the coils closer
By moving the coils apart
By increasing the number of turns of either coil
Permanent magnets can be found in
electric bells
earphones
relays
dy namic loudspeakers
Defined as the flux density produced in it due to its own induced magnetism
Magnetic field intensity
Electric field intensity
Electromagnetic field intensity
Intensity magnetization
What principle states that each electron in an atom must have a different set of quantum numbers?
Inclusion principle
Exclusion principle
Quantum principle
Electron principle
Hysteresis loss can be reduced by one of the following.
Increasing mmf of the circuit
Using material narrow hysteresis loop
Using ferromagnetic core
Laminating the magnetic circuit
What is the relative permittivity of air?
8.854 × 10^-12
4 × 10^7