CBSE-XI-Physics
35: Magnetic Field due to a Current
- #6A charged particle is moved along a magnetic field line. The magnetic force on the particle is
(a) along its velocity
(b) opposite to its velocity
(c) perpendicular to its velocity
(d) zero.digAnsr: dAns : (d) zero
The force on a charged particle q moving with velocity v in a magnetic field B is given by
`` \stackrel{\to }{F}=q(\stackrel{\to }{v}\times \stackrel{\to }{B})``
As the charge is moving along the magnetic line of force, the velocity and magnetic field vectors will point in the same direction, making a cross product.
`` (\stackrel{\to }{v}\times \stackrel{\to }{B})=0``
`` \Rightarrow \stackrel{\to }{F}=0``
So, the magnetic force on the particle will be zero.
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