An electric dipole antenna used to transmit radio waves is oriented vertically.At a point due south of the transmitter, what is the direction of the wave's magnetic field?

The right-hand rule helps us determine the direction of the magnetic field around a current-carrying wire. The rule states that if you point your thumb in the direction of the conventional current, your fingers will curl around the wire in the direction of the magnetic field.

A dipole antenna has two poles, one at the top and one at the bottom. The top pole acts as a current-carrying wire with the current going upward, while the bottom pole acts as a current-carrying wire with the current going downward. Let's apply the right-hand rule to the top and bottom poles of the antenna. Top pole: Place your right thumb pointing upward, in the direction of the conventional current in the top pole of the antenna. Your fingers will curl around the wire in the counterclockwise direction, indicating the magnetic field's direction around the top pole. Bottom pole: Place your right thumb pointing downward, in the direction of the conventional current in the bottom pole of the antenna. Your fingers will curl around the wire in the clockwise direction, indicating the magnetic field's direction around the bottom pole.

At a point due south of the transmitter, we need to consider the effects of both the top and bottom poles of the antenna. The magnetic field of the top pole has a counterclockwise direction, while the magnetic field of the bottom pole has a clockwise direction. At a point due south of the transmitter, these two magnetic fields will cancel each other out horizontally to create a magnetic field that is vertically oriented. Therefore, the direction of the magnetic field at a point due south of the transmitter will be vertically downward.