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प्रश्न
State any two causes of energy loss in actual transformers.
उत्तर
Following are the two cause of energy loss:
- Iron loss: Loss in the bulk of iron core due to the induced eddy currents. It is minimised by using thin laminated core.
- Current flowing through the primary and secondary coils will generate heat. Low resistance copper wires is used to reduce this effect.
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संबंधित प्रश्न
Describe briefly three main useful application of eddy currents ?
If the magnetic field outside a copper box is suddenly changed, what happens to the magnetic field inside the box? Such low-resistivity metals are used to form enclosures which shield objects inside them against varying magnetic fields.
Metallic (nonferromagnetic) and nonmetallic particles in a solid waste may be separated as follows. The waste is allowed to slide down an incline over permanent magnets. The metallic particles slow down as compared to the nonmetallic ones and hence are separated. Discuss the role of eddy currents in the process.
A metallic bob A oscillates through the space between the poles of an electromagnet (See the figure). The oscillations are more quickly damped when the circuit is on, as compared to the case when the circuit is off. Explain.
A metal sheet is placed in front of a strong magnetic pole. A force is needed to ______________ .
(a) hold the sheet there if the metal is magnetic
(b) hold the sheet there if the metal is nonmagnetic
(c) move the sheet away from the pole with uniform velocity if the metal is magnetic
(d) move the sheet away from the pole with uniform velocity if the metal is nonmagnetic.
Neglect any effect of paramagnetism, diamagnetism and gravity.
Why and where are eddy currents are undesirable? How are they minimized?
If the length of a simple pendulum increases by 5%, then its period shall increase by ______.
Eddy currents are also known as ______
Consider a metallic pipe with an inner radius of 1 cm. If a cylindrical bar magnet of radius 0.8 cm is dropped through the pipe, it takes more time to come down than it takes for a similar unmagnetised cylindrical iron bar dropped through the metallic pipe. Explain.
