An electron (m=9.1×10−31kg, ∣q∣=1.6×10−19C) is projected with speed 3.0×107ms−1 at an angle of 30∘ to a uniform magnetic field of magnitude 0.010T that runs along the field lines. What distance does the electron travel parallel to the field during one complete revolution about the field lines (pitch of the helical path)?
a) 0.107m
b) 0.054m
c) 0.093m
d) 0.047m