Test
MAGNETISM AND ELECTROMAGNETISM
Preguntas del test (28)
1A natural magnet is called
- Asteel
- Blodestone
- Cmagnetism
- Dsoft iron
2A magnet is able to attract
- Airon, aluminum and brass
- Biron, cobalt and zinc
- Ciron, copper and nickel
- Dnickel, cobalt and steel
3Externally, magnetic line of force travels
- Asouth to north
- Bnorth to south
- Cnegative to positive
- Din both directions
4A material commonly used for shielding or screening magnetism is
- Abrass
- Baluminum
- Ccopper
- Dsoft iron
5The magnetism that remains in a magnet after the magnetizing force has been removed is called
- Apermeability
- Binduction
- Cresidual
- Dsaturation
6Iron becomes magnetized by induction when it is
- Aheated
- Bsuspended east and west
- Cnear to one end of a magnet
- Dtreated with some chemicals
7Magnetic lines of force are called
- Ahysteresis
- Bcurrent
- Cflux
- Dmagnetomotive force
8The force between two magnetic poles varies with distance between them. The variation is
- Ain direct proportion to the distance
- Bin inverse proportion to the distance
- Cin direct proportion to the square of the distance
- Din inverse proportion to the square of the distance
9The magnetic potential in a magnetic circuit can be measured in terms of
- Afarads
- BM.M.F.
- Ccoulombs
- Dnone of these
10Permeance is analogous to
- Aconductance
- Bresistance
- Creluctance
- Dnone of these
11The permeability of a material means
- Astrength of permanent magnet
- Bstrength of an electromagnet
- Cthe magnetization left in the iron after exciting field has been removed
- Dthe conductivity of a material for magnetic lines of force
12When magnetic flux (Φ) and the area (A) under its influence are known, the magnetic flux density (B) can be given as
- AB = ΦA
- BB = Φ/A
- CB = A/Φ
- DB = ΦA2
13The relative permeability μr is given by
- AB/μr0H
- BB/H
- Cμ0/μ
- Dμ0/H
14Relative permeability of a material is given by (K is susceptibility of the material)
- A1 + μ0K
- B1 + K/μ0
- C1 + μ0/K
- Dμ0H
15The relative permeability of paramagnetic substance is
- Aslightly less than 1
- Bequal to 1
- Cslightly greater than 1
- Dvery much greater than 1
16The value of permeability for the free space is
- A4 x 10^-7 Hm-1
- B4π x 10^-7 Hm-1
- C4π x 10^7 Hm-1
- D1/4π x 10^-7 Hm-1
17The magnetization in any magnetic material appears as a result of
- Aelectrons orbital motion
- Belectron spin
- Cspin of the nucleus about its axis
- Dall of these
18The sum of the magnetic moments in unit volume of the solid is called
- Afield strength
- Bmagnetism
- Cpermeability
- Dsusceptibility
19Which of the following materials does not have permanent magnetic dipole
- Aparamagnetic
- Bantiferromagnetic
- Cdiamagnetic
- Dferrimagnetic
20Interaction between the neighboring dipoles is negligible in case of a
- Aparamagnetic material
- Bdiamagnetic material
- Cantiferromagnetic material
- Dferrimagnetic material
21Each ferromagnetic material has characteristic temperature above which its properties are quite different from those below that temperature. That temperature is called
- Atransition temperature
- BFaraday's temperature
- Cdemagnetization temperature
- DCurie' temperature
22The relative permability μ for iron is
- A5000
- B7000
- C3000
- D1000
23Which of the following material is used for making permanent magnets
- Acarbon steel
- Bplatinum cobalt
- CAlnico V
- DAll of these
24Which of the following has the highest value of relative permeability
- Airon
- Bsupermalloy
- CMu-metal
- D4% Si - Fe
25Ferrimagnetic materials generally behave as a
- Asemiconductor
- Bconductor
- Cinsulator
- Dany of A, B, or C
26Transformer cores operating at microwave frequency ranges are generally made up of
- Aferrites
- Bsilicon steel
- Csupermalloy
- Dalnico V
27The magnetic materials which can be easily magnetized in both directions are known as
- Asoft magnetic materials
- Bhard magnetic materials
- Clow hysteresis loss materials
- Dhigh hysteresis loss materials
28Eddy current loss can be minimized by
- Adecreasing the resistance of magnetic medium
- Bincreasing the resistance of magnetic medium
- Cdecreasing the permeability of magnetic medium
- Dnone of these
Información
- Descripción
- Engineering Test sobre MAGNETISM AND ELECTROMAGNETISM, creado por Owen Ryan Ang el 24/01/2020.
- Autor
- Owen Ryan Ang
- Idioma
- English
- Visitas
- 50
- Historial
- Creado el 24 ene 2020 · actualizado el 24 ene 2020
- Etiquetas
- Valoración
- Aún sin valoraciones Valora este test