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प्रश्न
Magnetic lines of force always cross each other
उत्तर
False
Magnetic lines of force never cross each other. If they cross the magnetic lines of force will show the two directions
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संबंधित प्रश्न
(a) Write the expression for the magnetic force acting on a charged particle moving with velocity v in the presence of magnetic field B.
The electric current flowing in a wire in the direction from B to A is decreasing. Find out the direction of the induced current in the metallic loop kept above the wire as shown.
A rod of length l is moved horizontally with a uniform velocity 'v' in a direction perpendicular to its length through a region in which a uniform magnetic field is acting vertically downward. Derive the expression for the emf induced across the ends of the rod.
A horizontal overhead power line carries a current of 90 A in east to west direction. What is the magnitude and direction of the magnetic field due to the current 1.5 m below the line?
A circular coil carrying a current I has radius R and number of turns N. If all the three, i.e. the current
I, radius R and number of turns N are doubled, then, the magnetic field at its centre becomes:
(a) Double
(b) Half
(c) Four times
(d) One fourth
The force between two parallel current-carrying conductors is F. If the current in each conductor is doubled, then the force between them becomes ______
A particle with charge q moves with a velocity v in a direction perpendicular to the directions of uniform electric and magnetic fields, E and B respectively, which are mutually perpendicular to each other. Which one of the following gives the condition for which the particle moves undeflected in its original trajectory?
The magnetic moment is NOT associated with ____________.
Direction of magnetic force on a positive charge moving in a magnetic field is given by ______.
- perpendicular to direction of velocity of charged particle.
-
perpendicular to direction of magnetic field.
-
parallel to direction of velocity of charged particle.
-
parallel to the direction of magnetic field.
Which one of the following is a correct statement about magnetic forces?
Figure shows a square loop. 20 cm on each side in the x-y plane with its centre at the origin. The loop carries a current of 7 A. Above it at y = 0, z = 12 cm is an infinitely long wire parallel to the x axis carrying a current of 10 A. The net force on the loop is ______ × 10-4 N.
A beam of light travelling along X-axis is described by the electric field Ey = 900 sin ω(t - x/c). The ratio of electric force to magnetic force on a charge q moving along Y-axis with a speed of 3 × 107 ms-1 will be : [Given speed of light = 3 × 108 ms-1]
Write the expression for the Lorentz force on a particle of charge q moving with a velocity `vecv` in a magnetic field `vecB`. When is the magnitude of this force maximum? Show that no work is done by this force on the particle during its motion from point `vecr_1` to point `vecr_2`.
An electron is moving along positive x-axis in a magnetic field which is parallel to the positive y-axis. In what direction will the magnetic force be acting on the electron?
Distinguish between the forces experienced by a moving charge in a uniform electric field and in a uniform magnetic field. (Any two points)
State the expression for the Lorentz force on a charge due to an electric field as well as a magnetic field. Hence discuss the magnetic force on a charged particle which is (i) moving parallel to the magnetic field and (ii) stationary.
A long straight wire AB carries a current of 5A. P is a proton travelling with a velocity of 2 × 106 m/s, parallel to the wire, 0.2 m from it and in a direction opposite to the current, as shown in Figure below. Calculate the force which magnetic field of the current carrying conductor AB exerts on the proton.
