What does a modulating signal that is much larger than the carrier create?

A modulating signal that is much larger than the carrier creates an amplitude modulation envelope. In amplitude modulation (AM), the strength (amplitude) of the carrier wave is varied in proportion to the modulating signal, which carries the actual information. When the modulating signal's amplitude exceeds that of the carrier, it influences the carrier's amplitude to create this envelope.

The modulation envelope is crucial in amplitude modulation as it visually represents the variations in amplitude of the carrier wave according to the modulating signal. It encapsulates the maximum and minimum levels that the carrier can achieve based on the modulation. This is particularly relevant when considering how audio signals, for example, modulate the amplitude of a radio frequency carrier to convey information.

In contrast, while frequency modulation alters the carrier frequency based on the modulating signal, and pulse modulation transmits information by varying the width or position of pulses, these do not necessarily create an envelope in the way described. Thus, the unique relationship between the large modulating signal and the resultant envelope distinctly highlights the characteristics of amplitude modulation.