What is the maximum number of electrons that can be accommodated in the last orbit of an atom?
Correct Answer :
C.
Related Questions
The force between two magnetic poles is _____ their poles strength.
equal to
directly proportional to
inversely proportional to
directly proportional to the square root of
What is the SI unit of magnetic flux?
Tesla
Weber
Maxwell
Gauss
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
A 6- V battery is connected across a solenoid of 100 turns having a resistance of 2 ?a Calculate the number of ampere turns?
Which element has four valence electrons?
Conductor
Insulator
Semiconductor
Semi- insulator
The magnetic materials should have a large hysteresis loss for one of the following applications.
Transformers
ACmotors
Permanent Magnets
DC generators
The electric potential at a point in air due to a charge is 21 V. If the air is replaced by a medium of relative permittivity of 3a then electric potential at that point will be
63 V
21 V
7 V
42 V
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 magnetic flux of 2000 lines is how many Maxwells?
What revolves about the positive nucleus in a definite orbit?
Atom
Proton
Electron
Neutron
If the value of 25 of a conductor is 1/230 per oCa then the value of 0is
1/180 peroC
1/150 per oC
1/280 per oC
1/230 per oC
A t/m is a unit of
Mmf
Emf
Reluctance
Magnetizing force
Ohm's law cannot be applied to which material?
Copper
Silver
Silicon carbide
Aluminum
Hydrogen is an example of a _____ material.
Paramagnetic
Diamagnetic
Ferromagnetic
N on- magnetic
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
A permanent magnet does not exert a force on
an unmagnetized iron bar
a magnetized iron bar
a moving electric charge
a stationary electric charge
When the relative permeability of a material is much greater than 1a it is called _______ material.
diamagnetic
ferromagnetic
paramagnetic
non-magnetic
The ratio of the total flux (flux in iron path) to the useful flux (flux in air gap)
Leakage flux
Leakage current
Leakage coefficient
Leakage factor
The resistance of a material is ____________ its area of cross-section.
directly proportional
independent of
inversely proportional to
equal to
A negatively charge body has
deficit of electrons
excess of protons
excess of electrons
deficit of neutrons
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
Magnetic effects of the earth as a huge magnet with north and south poles.
Diamagnetic
Ferromagnetic
Terrestrial magnetism
Terrestrial ferromagnetism
How many neutrons does a copper atom have?
If the magnetic material is located within a coil through which alternating current (60 Hz frequency) flowsa then __________ hysteresis loops will be formed
Flux density is measured in
Tesia
Weber
Ampere- turn
Maxwell
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
The B-H curve of ________ is not a straight line.
air
wood
silicon steel
soft iron
Residual magnetism refers to the flux densitya which exists in the iron core when the magnetic field intensity is
Minimized
Reduced to zero
Maximize
Unity
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
The magnetic field inside a solenoid
is zero
is uniform
increases with distance from the axis
decreases with distance from the axis