They are a method of storing information, but as there is no computer or digitizing element involved, it is not exactly a digital signal. It is an analog signal.
Transducer
With full double sideband AM the bandwidth of the modulated signal is twice that of the baseband information signal. With suppressed carrier single sideband AM the bandwidth of the modulated signal is identical to that of the baseband information signal. With vestigial sideband AM the bandwidth of the modulated signal is somewhere between the above two cases, depending on how much of the vestigial sideband is included.
zero bits
An analog or analogue signal is any continuous signal for which the time varying feature of the signal is a representation in respect to other time varying quantity, i.e., analogous to another time varying signal. Any information may be conveyed by an analog signal often such a signal is a measured response to changes in physical phenomena, such as sound, light, temperature, position, or pressure, and is achieved using a transducer. So, Analog signal is a medium to send information over distance ,the information cane be anything. The main disadvantage of Analog signals is they have larger noise . Alternating Current is defined as the behavior of Electric charge. Alternating Current is the movement of Electric current which is periodic and attains both positive and reverse direction (positive and negative) in its propagation whereas Direct Current only attains itself in one direction i.e positive cycle only. So,the difference is...Analog is the type of signals whereas Alternating is a behavior of Electric charge on its movement.
Information is captured in an electronic signal with patterns in the controlled flow of electrons through a circuit.
Electronic signal.
Frequency
A changing electric current that carries information is called a signal. This signal can be in the form of varying voltage levels or frequencies that can represent data or enable communication between electronic devices.
Batteries
You could be getting a signal from a tracer wire.
Weak signal depending upon the type of signal.
voltmeters
an amplifier.
An amplifier.
Transformer
Detector converts optical signal to electric signal