  Question

# A uniform magnetic field exists in the plane of the paper from left to right as shown in the figure. In the field, an electron and a proton move as shown. The electron and the proton experience forces. Both pointing into the plane of the paper Both pointing out of the plane of the paper Pointing into the plane of the paper and out of the plane of the paper, respectively Pointing out of the plane of the paper and into the plane of the paper, respectively

Solution

## The correct option is A Both pointing into the plane of the paper When a current carrying conductor is placed perpendicular to the direction of the magnetic field, the direction of the force acting on it is given by Fleming's left-hand rule. Since the direction of current is same as that of the motion of a positive charge, the direction of the force acting on it when it is moving perpendicular to the direction of magnetic field is the same as that acting on a current -carrying conductor placed perpendicular to the direction of magnetic field. The flow of current is in the direction opposite to flow of electrons by using Fleming's left-hand rule, we can say that the direction of force on the electron and proton is directed into the page.  Suggest corrections   