Question

An electron, moving toward the west, enters a uniform magnetic field. Because of this field the electron curves upward. What is the direction of the magnetic field and why? a)towards the west. b)downward. c)towards the north. d)towards the south. e)upward.

answer is north because,

using LEFT hand,  

1) looking at "electron curves upward" = sounds to me that the FORCE is OUT of the PAGE. (THUMB OUT OF THE PAGE) i need confirm on this part.

2) moving west, (MY INDEX POINT WEST)

3)(MY MID FINGER WHICH IS MAGNETIC FIELD POINTS TOWARD NORTH) so answer is NORTH.

READ, and IF I'M RIGHT THEN GOOD. IF NOT EXPLAIN.
I DON"T WANT YOUR ANSWER. READ MY QUESTIONS 1 2 3. OR NO CREDIT IS GIVEN.

Answer 1

We know that, magnetic force F = q v xB

j = -1 (-i ×B)

j = i x B

B is in -k direction, i.e. towards North direction

You are right, but you missed negative sign of electron, however it got compensated by the fact that you used your left hand instead of right. So if you intentionally used left in order to take negative sign of electron into account, then all is good.

1) Force is out of the page, you are right, I took out of the page as j, south as k, east as i.

2) Again right.

3) Right