Electricity and Magnetic Fundamentals

191. The permeability of a material having a flux density of 5 Wb/m∧2 is 10∧-5 H/m. What is the value of magnetizing force?

1. 5 X 10∧-5 N/Wb
2. 5OO X 10∧3 N/Wb
3. 4π X 10∧-7 N/Wb
4. 4π X 10∧7 N/Wb

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192. The permeability of permalloy is

1. Very much greater than permeability of air
2. Slightly greater than permeability of air
3. Slightly less than permeability of air
4. Equal to the permeability of air

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193. The permittivity of a material is given by one of the following formulas.

1. DE
2. E/D
3. D'2/E
4. D/E

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194. The phenomenon by which a magnetic substance becomes a magnet when it is place near a magnet

1. Magnetic effect
2. Magnetic phenomenon
3. Magnetic induction
4. Electromagnetic induction

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195. The phenomenon by which a subtracts pieces of iron

1. Magnetism
2. Electromagnetism
3. Naturalism
4. Materialism

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196. The phenomenon that when an electric current passes through an anisotropic crystal, there is an absorption or liberation of heat due to the non-uniformity in current distribution.

1. Bridgman effect
2. Corona effect
3. Dember effect
4. Destriau effect

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197. The physical motion resulting from the forces of magnetic fields is called

1. Motor action
2. Rotation
3. Repulsion
4. Torque action

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198. The point in a magnet where the intensity of magnetic lines of force is maximum

1. Magnetic pole
2. South pole
3. North pole
4. Unit pole

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199. The potential at a point due to a charge is 15 V. If the distance is increased three times, the potential at the point will be

1. 5 V
2. 18 V
3. 45 V
4. 15 V

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200. The process by which an emf and hence current is generated or induced in a conductor when there is a change in the magnetic flux linking the conductor is called

1. Electromagnetic induction
2. Mutual induction
3. Faraday's law
4. Electromagnetic interference

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