🔍 Key Concepts

• Modulation is how we encode information (voice/data) onto a carrier wave or pulses. • In some systems, the amplitude, frequency, or width/duration of a pulse can be changed to carry information. • Understand the difference between continuous wave modulation (like AM/FM) and pulse modulation types.

💭 Think About

• For each choice, ask: what exact characteristic of the signal is being changed to carry information—its height, its frequency, or the length of each pulse? • Which of these options specifically mentions or is associated with changing the time length (duration) of a pulse rather than its strength (height) or repetition rate? • Think about which terms are usually used with continuous waves (like radio broadcast) versus those used with pulsed signals (like radar).

✅ Before You Answer

• Match the phrase “varies the duration of the transmitted pulse” to the term that deals with time/width of a pulse, not its height or its frequency. • Eliminate any option that clearly refers to changing signal strength (how tall the wave is) or how often cycles occur per second. • Remember that pulse modulation terms usually include words like “height,” “position,” or “width,” each describing a different aspect of the pulse that can be varied.