Q. Two parallel beams of protons and electrons, carrying equal currents are fixed at a separation $d$. The protons and electrons move in opposite directions. $P$ is a point on a line joining the beams, at a distance $x$ from any one beam. The magnetic field at $P$ is $B$. If $B$ is plotted against $x$, which of the following best represents the resulting curve
A)
B)
C)
D)
Explanation
(c) The magnetic field at point to the right of the proton beam acts perpendicular to the paper inwards ($\times$). The magnetic field at points to the left of the electron beam acts perpendicular to the paper outward ($\bullet$).
Magnetic field at mid point $M$ is zero
Magnetic field at the points closer to proton beam acts perpendicular to the paper inwards ($i.e.,( \times )$) and at the points closer to electron beam it acts outwards $i.e.,\ ( \bullet )$. In the given options graph ($c$) satisfies all the condition
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.