The wavelength of an electromagnetic waves is also known as the period. the number of waves that pass a given point in space. the negative of the frequency. the spatial distance between two successive troughs. all of these are true.

The sentence can be completed as follows:

The wavelength of an electromagnetic waves is the spatial distance between two successive troughs.

Note that the wavelength of a wave can also measured as the spatial distance between two successive crests of the wave. Also note that the second part of the sentence ("also known as the period") is not true, because period is another thing (in fact, the period is the time interval between two successive troughs).

when earth is in rotational motion around the sun,it displaces from its place.

when a ball is placed on an inclined surface it does both the rotational and circular motion.

explanation:

higher potential

explanation:

because it is in a high speed so it must move into a of high potential