The force of attraction or repulsion between two magnetic poles is inversely proportional to the square of the distance between them. This is known as
Newton's first law
Faraday's first law of electromagnetic induction
Coulomb's first law
Coulomb's second law
Correct Answer :
D. Coulomb's second law
Related Questions
The K shell or the first shell has how many permissible number of orbiting electrons?
Small voltages generated by a conductor with current in an external magnetic field.
Skin effect
Magnetic effect
Hall effect
Flywheel Effect
If the distance between two magnetic poles decreases by 2 timesa the force between them
decreases two times
increases four times
increases two times
decreases four times
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
All matters (gasa liquid and solid) are composed of
Neutrons
Particles
Electrons
Atoms
The quantity 10^6 maxwells is equivalent to one
Weber
Gauss
Gilbert
Tesla
Back emf refers to the
Current equal to the applied emf
Opposing emf
Current opposing the applied emf
Voltage opposing the applied emf
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 ability of a mechanically stressed ferromagnetic wire to recognize rapid switching of magnetization when subjected to a dc magnetic field.
Wartheim effect
Wiedemann effect
Wiegand effect
Edison effect
Magnetic intensity is a
Phasor quantity
Physical quantity
Scalar quantity
Vector quantity
What is the SI unit of reluctance?
At
At/m
N/Wb
At/Wb
What is the diameter of an atom?
About 10^-10 m
About 10^-10 cm
About 10^-10 mm
About 10^-10 �m
The energy stored in an electrostatic field or electromagnetic field is called
Electromagnetic energy
Kinetic energy
Potential energy
R est energy
Electric field intensity at a point due to a given charge ______ if the relative permittivity of the medium decreases.
decreases
remains unchanged
increases
b ecomes zero
Lenz's law is the consequence of the law of conservation of
Energy
Charge
Field lines
Momentum
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
What solid has no defined crystal structure except perhaps in the arrangement of the nearest neighboring atoms or ions?
Crystalline
Amorphous
Polycrystalline
Poly amorphous
The ratio of the permeability of material to the permiabiity of air or vacuum.
Relative permeability
Relative permittivity
Relative conductivity
Relative reluctivity
The induced emf in a wire loop that is moved parallel to a uniform magnetic field is
Zero
Dependent on the area of the loop
Dependent on the shape of the loop
Dependent on the magnitude of the field
How many neutrons does a copper atom have?
Define as that pole which when placed in air from a similar and equal pole repels it with a force of newtons
North pole
South pole
Unit pole
Magnetic pole
The phenomenon by which a subtracts pieces of iron
Magnetism
Electromagnetism
Naturalism
Materialism
What determines the value of the temperature coefficient of resistance of a material?
length
cross-sectional area
volume
nature and temperature
When a wire loop is rotated in a magnetic field the direction of the induced emf changes one in every _______ revolution
Who discovereda the relationship between magnetism and electricity that serves as the foundation for the theory of electromagnetism?
Luigi Galvani
Hans Christian Oersted
Andre Ampere
Charles Coulomb
The air space between poles of magnets
Air gap
Free space
Vacuum
Atmosphere
Who demonstrated that there are magnetic effects around every current-carrying conductor and that current-carrying conductors can attract and repel each other just like magnets?
Luigi Galvani
Hans Christian Oersted
Charles Coulomb
Andre Ampere
The branch of Engineering which deals with the magnetic effect of electric current is known as
Magnetism
Electromagnetism
Electrical engineering
Electronics engineering
Electric field intensity at a point is numerically equal to ________ at that point.
potential gradient
potential difference
dielectric constant
the force
The emf produced in a wire by its motion across a magnetic field does not depend upon the
Diameter of the wire
Length of the wire
Orientation of the wire
Flux density of the field