Question

An electron travelling horizontally towards west enters into a magnetic field acting vertically down wards, It deflects towards.

• A. South
• B. North
• C. Vertically upwards
• D. North-East.

Answer 1

The correct option is B North

$\text{Solution}:$

1. Fleming's left hand rule states, that if we arrange our thumb, forefinger and middle finger of the left hand right angles to each other, then the thumb points towards the direction of the magnetic force, the forefinger points towards the direction of magnetic field and the middle finger points towards the current.

2. Therefore electron is deflected toward North.

$\text{Hence B is the correct option}$