Question #a69a3

1 Answer
Jun 6, 2016

c) positive #y#-direction

Explanation:

For a charge moving with velocity #vecv# in a magnetic field #vecB#, the direction of magnetic force is given by the direction of vector
#vecvxxvecB#
Given is #vecv=vhati#
To find the direction of magnetic field at the location of charge we use the right hand rule. The figure below is self explanatory.
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In the problem we see that in a right handed coordinate system
#vecB=-Bhat k#
Direction of magnetic force is given by
#hati xx-hatk=hatj#
which is the direction of positive #y#-axis