18. A metal disc rotates freely, between the poles of a magnet in the direction indicated. Brushes P and 2 make contact with the edge of the disc and the metal axle. What current, if any, flows through R? INT Dok

A metal disc is winging freely between the poles of an electromagnet, as shown in the figure. When the electromagnet is switched on, the disc comes to rest after a few oscillations. Explain why eddy currents are induced in the metal disc.

A metal disc is winging freely between the poles of an electromagnet, as shown in the figure. When the electromagnet is switched on, the disc comes to rest after a few oscillations. Use Faraday's law of electromagnetic induction to explain why an e.m.f. is induced in the disc.

A negatively charged disc is rotated clock-wise. What is the direction of the magnetic field at any point in the plane of the disc?

What are the differences between the flow of electric current through metal conductors and electrolytes?

A man of mass m_(1) stands on the edge of a horizontal uniform disc of mass m_(2) and radius R which is capable of rotating freely about a stationary vertical axis passing through its centre . The man walks along the edge of the disc through angle theta relative to the disc and then stops . find the angle through which the disc turned the time the man stopped . [(2m_(1)theta)/(2m_(1) + m_(2))]

A vertically metallic pole falls down through the plane of magnetic meridian. Will any emf be induced between its two ends?

A thin metal disc of radius r floats on water surface and bends the surface downwards along the perimeter making an angle theta with vertical edge of the disc of the disc. If the disc dispplaces a weight of water W and surface tension of water is T , then the weight of metal disc is