Question:
A uniform magnetic field exists in the plane of paper pointing from left to right as shown in figure. In the field, an electron and a proton move as shown.
The electron and proton experience
(a) forces, both pointing into the plane of paper
(b) forces, both pointing out of the plane of paper
(c) forces, pointing into the plane of paper and out of the plane of paper respectively.
(d) forces, pointing opposite and along the direction of the uniform magnetic field respectively.
Solution:
(a).
Explanation : Apply Fleming’s left hand rule and considering the flow of current in the direction of the movement of proton and in the direction
opposite to the movement of electron.