CBSE Class 12 Physics 2016 Delhi Set 1 Paper

Question : 13 of 26

Marks: +1, -0

(a) Write the expression for the magnetic force acting on a charged particle moving with velocity

v

in the presence of magnetic field B.
(b) A neutron, an electron and an alpha particle moving with equal velocities, enter a uniform magnetic field going into the plane of the paper as shown. Trace their paths in the field and justify your answer.

Solution:

(a) Expression for the magnetic force
(b) Trace of paths Justification
(a)

{F}↖{→}=q({V}↖{→} × {B}↖{→})

(Give Full credit of this part even if a student writes:

F=q V B sin \;θ \;\text " and "\;

Force

(F)

acts perpendicular to the plane containing

{V}↖{→}

and

{B}↖{→}

)
(b)

Justification : Direction of force experienced by the particle will be according to the Fleming's Left hand rule/(any other alternative correct rule.)

Go to Question:

Prev Question

Next Question