The direction of the electric field shown in each part of the Figure 24.5is that produced by the charge distribution in the wire. Justify the direction shown in each part, using the Coulomb force law and the definition of E=F/q, where qis a positive test charge.

Electromagnetic radiation is defined as electromagnetic field waves that propagate through space and carry electromagnetic radiant energy. Radio waves, microwaves, infrared, light, ultraviolet, X-rays, and gamma rays are all examples of electromagnetic radiation. The electromagnetic spectrum includes all of these waves.

By oscillating positive and negative charges inside the wire, an alternating current generator creates an oscillating electric field. The negative charge is on the upper end of the wire at the start of the oscillation, and the positive charge is on the lower end.

The electric field is known to point away from positive charges and towards negative charges. Because we hold the biggest charge, the field in the first image should point upward and be the strongest. There is no positive or negative charge after a quarter of a period, therefore the field in the source in the second photo is zero, but the already formed field has moved away from the source.

The charges have reversed as opposed to the beginning of the oscillation after half a period, so the field has the same magnitude as before but points in the opposite direction. The pre-existing field has moved away from the generator once more. After a whole period, we have the same charge distribution and field as before, as well as a sinusoidal electric field.

Therefore, the field is oriented towards the negative charge and away from the positive charge. The direction and amplitude of the electric field, as well as the amount and sign of the charge, fluctuate sinusoidally with time.