What revolves about the positive nucleus in a definite orbit?
Atom
Proton
Electron
Neutron
Correct Answer :
C. Electron
Related Questions
The unit of flux density is
Wb/m
Tesla
At/m
N/Wb
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
It is the reciprocal of reluctance and implies the case of readiness with which magnetic flux is developed.
R esistance
Conductance
Permeance
I nductance
A commercial alloy of aluminum nickela and iron with cobalta copper and titanium added to produce about 12 grades.
Alnico
Brass
Aluminum
Constantan
The energy stored in an electrostatic field or electromagnetic field is called
Electromagnetic energy
Kinetic energy
Potential energy
R est energy
Refers to the non- metallic materials that have the ferromagnetic properties of iron.
Ferrites
Ferromagnetic
Diamagnetic
Paramagnetic
What is the main advantage of temporary magnets?
The magnetic flux can be changed.
Hysteresis can be decreased.
Magnetic materials can be used.
Abundance of ferromagnetic material that can be temporarily magnetized.
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 magnetic flux through a coil changes. This results to the induced emf acting in a direction as to
Oppose the change
Aid the change
Either oppose or aid the change
Neither oppose nor aid the change
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
Two similar polesa each 1Wba placed 1 m apart in air will experience a repulsive force of
63000 N
63 × 10^-3 N
8 × 10^12 N
796 kN
What is the other name for dielectric strength?
Breakdown voltage
Electric intensity
Potential gradient
Dielectric constant
What is the SI unit of conductivity?
Ohms/m
Ohms-m
Siemens-m
Siemens/m
Electric lines of force leave or enter the charge surface at an angle of
30o
45 o
90o
depending upon the angle of launch and entry
The ratio between the intensity of magnetization produced in a substance to the magnetizing force producing it
Magnetic Reluctivity
Magnetic Resistivity
Magnetic susceptibility
Magnetic conductivity
__________ is a substance of whose molecules consist of the same kind of atom.
Mixture
Compound
Element
Isotope
The electric field intensity between the parallel plate air capacitor is 20 N/C. If an insulating slab of relative permittivity 5 is placed between the platesa then electric field intensity will be
20 N/C
100 N/C
4N/C
40 N/C
What is the measure of the density and sign of the electric charge at a point relative to that at some time?
Electric potential
Electric charge
Electric current
Electric intensity
Magnetic effects of the earth as a huge magnet with north and south poles.
Diamagnetic
Ferromagnetic
Terrestrial magnetism
Terrestrial ferromagnetism
The phenomenon by which a magnetic substance becomes a magnet when it is place near a magnet
Magnetic effect
Magnetic phenomenon
Magnetic induction
Electromagnetic induction
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
Defined as the number of lines per unit area through any substance in a plane at right angles to the lines of force
Flux
Flux lines
Flux density
Flux intensity
What bond is formed when one or more electrons in the outermost energy orbit of an atom are transferred to another?
Ionic
Covalent
Metallic
Van der Waals
The science of adapting electronics to aerospace flight.
Avionics
Aerotronics
Aerodynamics
Astrionics
The point in a magnet where the intensity of magnetic lines of force is maximum
Magnetic pole
South pole
North pole
Unit pole
If the number of valence electrons of an atom is exactly 4a then the substance is called
a semiconductor
a conductor
an insulator
a cryogenic conductor
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 potential at a point due to a charge is 15 V. If the distance is times, the potential at the point will be
5 V
18 V
45 V
15 V
A one cubic cm of copper has how many free electrons at room temperature?
80 × 10^18
8.5 × 10^22
20 × 10^10
50 × 10^20
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