Conventional current and charge flow

QUESTION: Which one of the following situations results in a conventional electric current that flows westward?



a beam of protons moves eastward
a electric dipole moves westward
a beam of electrons moves westward
a beam of electrons moves eastward
a beam of neutral atoms moves westward

Answer

As I am sure you know the conventional direction of electric current is the movement of charges from positive to negative – in other words a flow of positive charges.

We need to look at the options and see if we can find positive charges moving to the west – or of course negative charges moving to the east.

In your options the only possibility is: a beam of electrons moves eastward

The others are no good because:
a beam of protons moves eastward - positive charges moving east
a electric dipole moves westward - a dipole has no net charge
a beam of electrons moves westward - negative charges moving west
a beam of neutral atoms moves westward - neutral atoms have no net charge