which way am i supposed to point my thumb because for me it keeps going right. what’s the difference between point P and R
for finding magnetic field produced by a current carrying conductor, using your right hand point your thumb in the direction of current, and curl your fingers kinda like a thumbs up; the direction your fingers curl is the direction of the B field.
point R is in between both the conductors, so it will be affected by B fields produced by each conductor; because it’s equidistant from each of the two wires, the B fields cancel out (this can be seen via right hand rule, one B field is pointing down, the other up)
point P is sufficiently far from the conductor on the right, so we can choose to ignore it (we can assume the B field produced by the conductor on the right will have minimal effect there); then we only have to consider the B field produced by the conductor on the left, and the right hand rule produces the result