Which of the following best describes a 'modulated signal'?

Which of the following best describes a 'modulated signal'?

• A. A signal that carries information
• B. A raw signal
• C. A signal that has been distorted
• D. A noise signal

Answer: (A)

A modulated signal refers specifically to a transmission that has been altered in some way to encode information. This modulation process involves varying certain characteristics of a carrier signal—such as its amplitude, frequency, or phase—in accordance with the information being sent. By doing this, the signal can effectively carry data across various mediums, whether it's for radio, television, or data communications. The essence of modulation is to allow a low-frequency signal that may not be able to propagate effectively on its own to be combined with a higher frequency carrier, enabling it to cover longer distances and overcome potential interference. Thus, when you say a signal carries information, that aligns perfectly with the definition of a modulated signal, making the statement accurate.

A modulated signal refers specifically to a transmission that has been altered in some way to encode information. This modulation process involves varying certain characteristics of a carrier signal—such as its amplitude, frequency, or phase—in accordance with the information being sent. By doing this, the signal can effectively carry data across various mediums, whether it's for radio, television, or data communications.

The essence of modulation is to allow a low-frequency signal that may not be able to propagate effectively on its own to be combined with a higher frequency carrier, enabling it to cover longer distances and overcome potential interference. Thus, when you say a signal carries information, that aligns perfectly with the definition of a modulated signal, making the statement accurate.