Defined as the ratio of the volume occupied by the atoms or ions in a unit cell divided by the volume of the unit cell and is used to measure the compactness of a crystal.
Aatomic packing factor (APF)
Bionic packing ratio (IPR)
Catomic compacting factor (ACF)
Dionic compacting ratio (ICR)
#22
Electric current in a wire is the flow of _____ electrons.
Afree
Bvalence
Cbound
Dloose
#23
Electric flux is a/an _______ quantity.
Ascalar
Bvector
Cabsolute
Drelative
#24
Electrons at the conduction band are called
Afree electrons
Bvalence electrons
Cdeep state electrons
Dshallow state electrons
#25
Flux density is measured in
ATesla
BWeber
CAmpere-turn
DMaxwell
#26
Germanium atom has _____ protons and _____ electrons.
A32, 32
B32, 42
C42, 32
D34, 34
#27
How many electrons are there in the fourth orbit of a copper electron
A1
B2
C3
D4
#28
How many neutrons does Uranium 238 have?
A146
B148
C147
D149
#29
Ideally, all atoms have the same number of positively charged protons and negatively charged electrons, and is therefore considered as
Aelectrically neutral
Bphysically stable
Cmagnetically aligned
Dtechnically rigid
#30
If a magnetic flux cuts across 200 turns at a rate of 2 Wb/s, the induced voltage according to Faraday's law is about
A400 V
B100 V
C200 V
D600 V
#31
If the electrical current carried by each of the two long parallel wire is doubled, and their separation is also doubled, the force between them
Aalso doubles
Bincreases by a factor of four
Cdecreases by a factor of four
Ddecreases by a factor of two
#32
If the magnetic flux through a coil changes, the induced EMF acts in such a direction as to
Aoppose that change
Bmagnify that change
Caugment that change
Damplify that change
#33
If the magnetic material is located within a coil through which alternating current (60 Hz frequency) flows, then _____ hysteresis loops will be formed every second.
A60
B120
C30
D180
#34
In electro-mechanical conversion devices like generators and motors, the reason why a small air gap is left between the rotor and stator is to
Apermit mechanical clearance
Bincrease flux density in air gap
Cdecrease the reluctance of magnetic path
Dcomplete the magnetic path
#35
It is an arrangement of silicon atoms combined to form a solid such that there are now 8 electrons in the valence shell.
Acrystal
Bbonding
Crecombination
Dsolid silicon
#36
It refers to any of the over 100 different substances which have never been separated into simpler substances by chemical means and which alone or in combination constitute all matter.
Aelement
Batom
Choles
Delectrons
#37
K shell means
Afirst orbit
B2nd orbit
C3rd orbit
D4th orbit
#38
Materials whose permeabilities are slightly greater than that of free space
Aparamagnetic
Bnon-magnetic
Cferromagnetic
Ddiamagnetic
#39
Maximum no. of orbiting electrons at the first or K shell
