What determines the atomic number of an element?
The number of protons
The number of electrons
The number of neutrons
The number of neutrons and protons
Correct Answer :
A. The number of protons
Related Questions
The permeability of permalloy is
Very much greater than permeability of air
Slightly greater than permeability of air
Slightly less than permeability of air
Equal to the permeability of air
A 6- V battery is connected across a solenoid of 100 turns having a resistance of 2 ?a Calculate the number of ampere turns?
Electric field intensity at a point is numerically equal to ________ at that point.
potential gradient
potential difference
dielectric constant
the force
If the right handed bottle-opener cork screw is assumed to be along the conductor so as to advance in the direction of current flow, the motion of its handle will indicate the direction of magnetic flux produced around the conductor. This is known as
Right hand rule
Left hand rule
Cork screw rule
End rule
When a conductor is stationary and the magnetic field is moving or changing the emf induced is called
Statically induced emf
Mutually induced emf
Self induced emf
Dynamically induced emf
Which of the following is a vector quantity?
Magnetic potential
Magnetic field intensity
Magnetic permeability
F lux density
If the number of valence electrons of an atom is less than 4a the substance is called
a conductor
a semiconductor
an insulator
a superconductor
The simplest type of atom to exist is the ______ atom.
Helium
Hydrogen
Boron
Oxygen
Used to maintain strength of magnetic field
Container
Air gap
Keeper
S ource
The quantity of magnetism retained by a magnetic material after withdrawal of the magnetizing force is called
Leftover magnetism
Hysteresis
Residual magnetism
Coercivity
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
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
A positively charged body has
deficit of electrons
excess of neutrons
excess of electrons
deficit of protons
Amorphous solid is also called
Crystalline
Non- crystalline
Polycrystalline
Homogenous
States that the ratio of the thermal conductivity is proportional to the absolute temperature for all metals.
Wien's displacement law
Hartleys law
Hall's law
Wiedemann Franz law
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
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
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
The temperature coefficient of resistance of eureka is
p ositive
negative
almost zero
i nfinite
A length of wire has a resistance of 10 ohms. What is the resistance of a wire of the same material three times as long and twice the cross-sectional area?
30 ohms
20 ohms
15 ohms
7 ohms
If the relative permittivity of a material is 10a then its permittivity is
4 × 10^7F/m
4 × 10^-6 F/m
8.854× 10^-11 F/m
8.854 × 10^-12 F/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
Hipernik is an alloy containing __________ iron and __________ nickel.
40% ; 60%
60% ; 40%
50% ; 50%
70% ; 30%
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
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
Who demonstrated the theory of electromagnetic induction in 1831?
Michael Faraday
Andre Ampere
James Clerk Maxwell
Charles Coulomb
One of the common application of an air- cored choke.
Radio frequency
Audio frequency
Power supply
Power transformer
The phenomenon by which a subtracts pieces of iron
Magnetism
Electromagnetism
Naturalism
Materialism
Who discovered that a current-carrying conductor would move when placed in a magnetic field?
Michael Faraday
Andre Ampere
Hans Christian Oersted
Gustav Robert Kirchhoff
Referred to as the specific reluctance of a material
Resistivity
Reluctivity
Conductivity
Permeability