When a metallic plate swings between the poles of a magnet

1. no effect of the plate

2. eddy current are set up inside the plate and the direction of the current is along the motion of the plate

3. eddy current are set up inside the plate and then direction of the current oppose the motion of the plate

4. eddy currents are set up inside the plate

Subtopic:  Eddy Current |
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The core of any transformer is laminated. By doing this we are ensuring that:
 
1. transformer is light weighted.
2. the efficiency of transformer is low.
3. losses due to eddy currents are minimized.
4. transformer becomes robust and sturdy.
Subtopic:  Eddy Current |
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Eddy currents can be minimised by:
1. reducing relative motion between the core and magnet in an electric motor
2. by making the core of thin laminations
3. by increasing the conductor cross-sectional area
4. both (1) and (2) are correct
Subtopic:  Eddy Current |
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A metal plate is getting heated. It can be because
a. a direct current is passing through the plate.
b. it is placed in a time varying magnetic field.
c. it is placed in a space varying magnetic field, but does not vary with time.
d. a current (either direct or alternating) is passing through the plate.
Choose the correct option:
1. (a), (c)
2. (a), (b), (d)
3. (b), (d)
4. (c), (d)
Subtopic:  Eddy Current |
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Eddy currents are useful in several practical applications, but not in all. In which of the following devices are eddy currents not used?
1. Electromagnetic braking system in trains
2. Induction furnace
3. Eddy-current speedometer
4. Venturi meter
Subtopic:  Eddy Current |
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