Advertisements
Advertisements
प्रश्न
The motion of copper plate is damped when it is allowed to oscillate between the two poles of a magnet. What is the cause of this damping?
Advertisements
उत्तर
As the copper plates oscillate in the magnetic field between the two poles of the magnet, there is a continuous change of magnetic field flux linked with the plate. Due to this, eddy currents are set up in the copper plate which try to oppose the motion of the plate according to the Lenz’s law and finally bring it to rest.
संबंधित प्रश्न
Find the condition under which the charged particles moving with different speeds in the presence of electric and magnetic field vectors can be used to select charged particles of a particular speed.
Two proton beams going in the same direction repel each other whereas two wires carrying currents in the same direction attract each other. Explain.
Consider a long, straight wire of cross-sectional area A carrying a current i. Let there be n free electrons per unit volume. An observer places himself on a trolley moving in the direction opposite to the current with a speed \[v = \frac{i}{\text{nAe}}\] and separation from the wire by a distance r. The magnetic field seen by the observer is very nearly
Consider the situation shown in figure. The wire PQ has mass m, resistance r and can slide on the smooth, horizontal parallel rails separated by a distance l. The resistance of the rails is negligible. A uniform magnetic field B exists in the rectangular region and a resistance R connects the rails outside the field region. At t = 0, the wire PQ is pushed towards right with a speed v0. Find (a) the current in the loop at an instant when the speed of the wire PQ is v, (b) the acceleration of the wire at this instant, (c) the velocity vas a functions of x and (d) the maximum distance the wire will move.

A magnetic field that varies in magnitude from point to point but has a constant direction (east to west) is set up in a chamber. A charged particle enters the chamber and travels undeflected along a straight path with constant speed. What can you say about the initial velocity of the particle?
A charged particle moves through a magnetic field perpendicular to its direction. Then ______.
-
The presence of a large magnetic flux through a coil maintains a current in the coil if the circuit is continuous.
-
A coil of a metal wire kept stationary in a non– uniform magnetic field has an e.m.f induced in it.
-
A charged particle enters a region of uniform magnetic field at an angle of 85° to the magnetic lines of force, the path of the particle is a circle.
-
There is no change in the energy of a charged particle moving in a magnetic field although a magnetic force is acting on it.
If an electron is moving with velocity `vecnu` produces a magnetic field `vec"B"`, then ______.
A moving charge will gain kinetic energy due to the application of ______.
