# Doubt from magnetics

For 20 if I take perpendicular entering in 2nd region option (a) is coming

@akash_2020 bro why will the perpendicular enter??..clearly radius of circle it will define will be greater than the d..it will enter while it will make an arc..

Yes it will not enter perpendicular but if we don't take perpendicular entering option are not matching

It will enter perpendicular to its previous radius and answer will be a option. Just as it enters into new section it’s radius will change to direction such it remains perpendicular to entering velocity.

A and B?

Fir first one,construct full circle by extending the arc and make right triangle to find angle(60°) and then solve for the second area

For the second just take the average i.e

[1/2ωl²(0+B-2B+4B)]/4

Ignore this post.