Answer:

Explanation:
Potential energy is minus the integral of Fdx. Doing the integration yields:



so


Now for x=3.0m


Answer:
ratio =0.3075 T
Explanation:
The magnetic field B creates a force on a moving charge such that

Now this causes a centripetal acceleration

so
...........(i)
...............(ii)
If accelerating potential V is same and then kinetic energy equals the potential energy difference

put these value in equation (ii)
simplifying we get

for same location r will be same in both case
..............(iii)
..........(iv)
dividing (iv) and (iii) equation we get



so on solving we get
=0.3075 T
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