15. In MODEMS A.Several digital signals are multiplexed B.A digital signal changes some characteristic of a carrier wave C.Digital signal is amplified D.All of the above E.None of the above
Option B Solution: A modem is a device or program that enables a computer to transmit data over, for example, telephone or cable lines. Computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analog waves.
