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 the 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) force pointing opposite and along the direction of the uniform magnetic field respectively
The correct Answer is:
A
Direction of current is opposite to the direction of movement of electron. So, current will move upwards. If index finger is showing the direction of magnetic field, ring finger is showing the direction of current, then direction of thumb is into the paper.