Este Quiz é cronometrado.
Você tem 30 minutos para completar as 25 questões deste quiz..
Electrons are ALWAYS present in every material.
True
False
What is the charge of an electron?
1.602 x 10-19 coulomb
9.109 x 10-27 coulomb
No charge
None of the above
The nearer the electron from the nucleus, the higher its energy level.
Who improved Bohr’s atomic model?
Ernest Rutherford
A.G.A.A Volta
John Travolta
Jeremy Virata
Materials with exactly 4 valence electrons.
Conductor
Semiconductor
Insulator
The region where free electrons are said to be present
Conduction band
Valence band
Rubber band
Energy band
A positive electric charge can be destroyed by a negative electric charge.
Electronegative elements give up electrons to produce negative ions.
When two or more charges exert forces simultaneously on another charge, the total force acting on the charge is the vector sum of the individual forces exerted by each charge. This is known as the:
Principle of superimposition
Principle of electromotive force
Principle of electro-position
Principle of superposition
For any closed system, the total electric flux passing through that surface is:
Directly proportional to the total charge inside the system
Inversely proportional to the total charge inside the system
Directly proportional to the half of the total charge inside the system
Inversely proportional to the half of the total charge inside the system
In Gauss’s law, the electric field E MUST BE normal or perpendicular to the Gaussian surface.
What is the unit of electrical potential difference?
Joules
Coulombs
Volts
Ampere
The production of electric current, potential or voltage due to magnetism is called:
Electromagnetism
Electromagnetic Induction
Electromagnetic Conduction
Electromagnetic Production
The more domains aligned, the stronger is the magnetic field.
At saturation point, almost all domains are already aligned. So further increase in the magnetizing force will:
Add a large amount of domain alignments and therefore a huge increase in magnetic field
Add a few amount of domain alignments and therefore a huge increase in magnetic field
Add a large amount of domain alignments and therefore a little increase in magnetic field
Add a few amount of domain alignments and therefore a little increase in magnetic field
What is the source of magnetic fields:
Permanent Magnet
Earth itself
Current-Carrying Conductor
Only Permanent Magnet and Earth itself
All of the above
Nonmagnetic materials ______ magnetism to pass through them.
Allow
Does not allow
Both
It is used to make powerful permanent magnets. Very hard and difficult to machine; usually cast in their final shape; subject to strict procedure of heat and magnetic field treatment.
Aluminum, nickel, copper
Aluminum, nitrogen, copper
Copper, nitrogen, alloys
Cobalt, aluminum, nickel
19. ALL ferromagnetic materials have hysteresis loops. Temporary magnets have low retentivity.
True; True
True; False
False; True
False; False
The flux that does not follow to its intended path in a magnetic circuit.
Misplaced flux
Misdirected flux
Flowing-out flux
Leakage flux
Flux ALWAYS follows its intended path.
What is the reciprocal of reluctance?
Permiance
Performance
Personance
Permeance
What is the symbol for magnetic circuit’s flux density?
J
P
B
G
The concept whereby a small voltage is generated by a conductor with current in an external magnetic field is known as:
Faraday effect
Wiegand effect
Hall effect
Lenz’ effect
Coulomb is the SI unit of charge, how about cgs?
Statcoloumb
Static Unit
Electron Volt
Electron Unit
Find the dielectric constant of air.
Approximately 2
Approximately 1
Approximately - 1
Approximately - 2
