Advertisements
Advertisements
प्रश्न
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?
Advertisements
उत्तर
The initial velocity of the particle is either parallel or anti-parallel to the magnetic field. Hence, it travels along a straight path without suffering any deflection in the field.
संबंधित प्रश्न
A point charge q moving with speed v enters a uniform magnetic field B that is acting into the plane of the paper as shown. What is the path followed by the charge q and in which plane does it move?
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?
Two long straight parallel conductors carrying steady currents I1 and I2 are separated by a distance 'd'. Explain briefly, with the help of a suitable diagram, how the magnetic field due to one conductor acts on the other. Hence deduce the expression for the force acting between the two conductors. Mention the nature of this force.
A moving charge produces
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 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.
Assertion(A): A proton and an electron, with same momenta, enter in a magnetic field in a direction at right angles to the lines of the force. The radius of the paths followed by them will be same.
Reason (R): Electron has less mass than the proton.
Select the most appropriate answer from the options given below:
A moving charge will gain kinetic energy due to the application of ______.
A deuteron and an alpha particle having equal kinetic energy enter perpendicular into a magnetic field. Let `r_d` and `r_alpha` be their respective radii of the circular path. The value of `(r_d)/(r_alpha)` is equal to ______.
A circular coil of radius 10 cm is placed in a uniform magnetic field of 3.0 × 10-5 T with its plane perpendicular to the field initially. It is rotated at constant angular speed about an axis along the diameter of coil and perpendicular to magnetic field so that it undergoes half of rotation in 0.2 s. The maximum value of EMF induced (in µV) in the coil will be close to the integer ______.
A thin strip 10 cm long is on a U-shaped wire of negligible resistance and it is connected to a spring of spring constant 0.5 Nm-1. The assembly is kept in a uniform magnetic field of 0.1 T. If the strip is pulled from its equilibrium position and released, the number of oscillations it performs before its amplitude decreases by a factor of e is N. If the mass of the strip is 50 grams, its resistance is 10 Ω, and air drag is negligible, N will be close to ______.
A wire carrying current i has the configuration shown in figure. For the magnetic field to be zero at the centre of the circle, θ must be:
A conductor ABOCD moves along its bisector with a velocity 1 m/s through a perpendicular magnetic field of 1 wb/m2, as shown in figure. If all the four sides are 1 m length each, then the induced emf between A and Din approx is ______V.
A charged particle is accelerated through a potential difference of 12 kV and acquires a speed of 106 ms-1. It is projected perpendicularly into the magnetic field of strength 0.2 T. The radius of the circle described is ______ cm.
Protons and singly ionized atoms of U235 and U238 are passed in turn (which means one after the other and not at the same time) through a velocity selector and then enter a uniform magnetic field. The protons describe semicircles of radius 10 mm. The separation between the ions of U235 and U238 after describing the semicircle is given by ______.
