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प्रश्न
In which of the following devices, the eddy current is not used ______
पर्याय
Electromagnet
Induction furnace
Electric heater
Magnetic breaking in train
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उत्तर
In which of the following devices, the eddy current is not used Electric heater.
संबंधित प्रश्न
State any two causes of energy loss in actual transformers.
Give one example of use of eddy currents.
How are eddy currents produced ?
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.
How are eddy currents generated in a conductor which is subjected to a magnetic field?
Write two examples of their useful applications .
How can the disadvantages of eddy currents be minimized?
Why and where are eddy currents are undesirable? How are they minimized?
A constant retarding force of50 N is applied to a body of mass 20 kg moving initially with a speed of 15 ms-1. How long does the body take to stop?
If the length of a simple pendulum increases by 5%, then its period shall increase by ______.
For high frequency, capacity offers
Which one is not an application of eddy current?
Eddy currents are also known as ______
A metal plate is getting heated. It can be because ______.
- a direct current is passing through the plate.
- it is placed in a time varying magnetic field.
- it is placed in a space varying magnetic field, but does not vary with time.
- a current (either direct or alternating) is passing through the plate.
