Who demonstrated the theory of electromagnetic induction in 1831?
Michael Faraday
Andre Ampere
James Clerk Maxwell
Charles Coulomb
Correct Answer :
A. Michael Faraday
Related Questions
One weber of flux is equal to _______ magnetic lines of force.
10^6
10^10
4 × 10^7
10^8
A magnetic flux of 2.5 x10^4 Wb through an area of 5 x10^4 square meters results in
5 Wb
0.5 Tesia of flux density
5x 10^-5 Wb of flux
5000 Tesia of flux density
Back emf refers to the
Current equal to the applied emf
Opposing emf
Current opposing the applied emf
Voltage opposing the applied emf
This paper does not exhibit electricity because it contains the same number of
protons and electrons
neutrons and electrons
neutrons and positrons
atoms
A germanium atom has an atomic weight of72. How many neutrons are there?
The magnetic field inside a solenoid
is zero
is uniform
increases with distance from the axis
decreases with distance from the axis
A magnetic field is
The current flow through space around a permanent magnet
The force set up when current flows through a conductor
The force that drives current through a resistor
The force between the plates of a charged capacitor
The phenomenon by which a subtracts pieces of iron
Magnetism
Electromagnetism
Naturalism
Materialism
The energy stored in an electrostatic field or electromagnetic field is called
Electromagnetic energy
Kinetic energy
Potential energy
R est energy
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
The electric potential across part AB of a circuit is 5 V; point A being at higher potential. If a charge of 5 Cmoves from A to Ba then energy released as
5 joules
25 joules
10 joules
100 joules
When the relative permeability of a material is slightly more than 1a it is called ______ material.
diamagnetic
ferromagnetic
paramagnetic
non-magnetic
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
If the resistance of a material 2 m long and 2 m^2 in area of cross-section is 1.6 ×10^-8 ?a then its resistivity is
3.2 × 10^-8 ?-m
1.6 × 10^-8 ?-m
0.64 × 10^-8 ?-m
0.16 × 10^-8 ?-m
The lagging effect between flux density of the material and the magne
Permeance
Eddy current
Hysteresis
R eluctance
Electronic current in a wire is the flow of ____________ electrons.
free
valence
bound
loose
Gases whose particles are charged are known as
Conductors
Insulators
Gaseous Conductors
Plasma
The diameter of a hydrogen atom is approximately ______ cm.
1.1 x 10^-6
1.1 x 10^7
1.1 x 10^-8
1.1 x 10^-9
The electrons in the last orbit of an atom are called _______ electrons.
free
valence
bound
thermionic
A law establishing the fact that the algebraic su of the rises and drops of the mmf around a closed loop of a magnetic circuit is equal to zero.
Kirchhoff's circuital law
Maxwell's circuital law
Ampere's circuital law
Coulomb's circuital law
Permanent magnets can be found in
electric bells
earphones
relays
dy namic loudspeakers
A magnetic material losses its ferromagnetic properties at a point called
Curie temperature
Inferred absolute temperature
Room temperature
Absolute temperature
Hysteresis is a phenomenon of _________ in a magnetic circuit.
setting up constant flux
lagging of H behind B
lagging B behind H
leading B ahead H
When a wire loop is rotated in a magnetic field the direction of the induced emf changes one in every _______ revolution
The K shell or the first shell has how many permissible number of orbiting electrons?
Theory of ferromagnetic phenomena which assumes each atom is a permanent magnet which can turn freely about its center under the influence of applied field and other magnets.
Ewing's theory of ferromagnetism
Oersted's ferromagnetism theory
Maxwell's magnetic theory
Ampere's circuital law
One of the solid structures in which the position of the atoms or ions are predetermined
Crystalline solid
Amorphous solid
Polycrystalline solid
Poly amorphous solid
Which of the following electric quantities is vector in character?
Field
Charge
Energy
Potential Difference
What is the reluctance of a magnetic path having a length of 2x 10^-3m and crosssectional area of 2.5 x 10^-3 m^2?
6366 A, t/Wb
6000 A, t/Wb
8x10^-3 A, t/Wb
0.8 A, t/Wb
Which of the following materials has the highest dielectric strength?
Glass
Oiled paper
Mica
Air