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.Management Sciences
Category: Magnetism and Electromagnetism
The attraction capacity of electromagnet will increase if the_______________?
A. core length increases i
B. core area increases
C. flux density decreases
D. flux density increases
Which of the following statements is correct ?
A. The magnetic flux inside an exciting coil is lower than its outside surface
B. The magnetic flux inside an exciting coil is zero
C. The magnetic flux inside the exciting coil is greater than its outside surface
D. The magnetic flux inside the exciting coil is same as on its outside surface
Indicate which of the following material does not retain magnetism permanently
A. Soft iron
B. Stainless steel
C. Hardened steel
D. None of the above
Substances which have permeability less than the permeability of free space are known as_____________?
A. ferromagnetic
B. paramagnetic
C. diamagnetic
D. bipolar
For which of the following materials the saturation value is the highest ?
A. Ferromagnetic materials
B. Paramagnetic materials
C. Diamagnetic materials
D. Ferrites
Susceptibility is positive for______________?
A. non-magnetic substances
B. diamagnetic substances
C. ferromagnetic substances
D. none of the above
Which of the following statements is correct ?
A. The conductivity of ferrites is better than ferromagnetic materials
B. The conductivity of ferromagnetic materials is better than ferrites
C. The conductivity of ferrites is very high
D. The conductivity of ferrites is same as that of ferromagnetic materials
Magnetising steel is normals difficult because____________?
A. it corrodes easily
B. it has high permeability
C. it has high specific gravity
D. it has low permeability
The materials are a bit inferior conductors of magnetic flux than air
A. ferromagnetic
B. paramagnetic
C. diamagnetic
D. dielectric
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