Friday, July 4, 2008

g, E and B vector addition


Since E field topic is so badly understood, why not do 3 in 1 .At a point X along the line joining this to circles.Let us find the g,E and B field at X.
g field:g = g1 + g2 ( draw g towards the mass at all times, one has to be negative as they are opp in direction )
E field : E = E1 + E2 ( draw E away from charge if positive and towards if negative at point X. Consider if they are the same direction or opposite to either add of subtract the E magnitudes)
B field B: B1 + B2 ( draw up or down from X depending the current is into page (CW) or out of page (ACW) . If both current point IN then at Point X B1 and B2 is up and down and therefore need to subtract.
All the above are just dealing with vectors in general and therefore resultant vector is always written as add but need to subtract if it is pointing in opposite direction.
The magnitudes have to be calculated separately using their respective formulas:\
g = GM/r2, E = kQ/r2 and B = kI/r2(not needed)