Difficulty: Easy
Correct Answer: Modulator Demodulator
Explanation:
Introduction / Context:
Before broadband and fiber became common, personal computers reached the internet via telephone lines using a modem. Even today, cable and cellular systems use devices colloquially called modems. Understanding what the name means reveals the core function of these devices.
Given Data / Assumptions:
Concept / Approach:
“Modem” combines Modulator and Demodulator. Modulation maps digital data onto an analog or RF carrier so it can traverse a channel (for example, copper pair, coax, radio). Demodulation performs the inverse mapping to recover bits at the receiver. The same principle underpins dial-up, ADSL/VDSL, DOCSIS cable, and LTE/5G data links, though implementations differ.
Step-by-Step Solution:
Identify the two halves of the portmanteau: “mo” + “dem”.Recall: mo = modulator, dem = demodulator.Select the option with exact wording “Modulator Demodulator”.
Verification / Alternative check:
Product manuals and standards (for example, V-series for dial-up, DOCSIS for cable) explicitly describe modulation schemes (QAM, OFDM) executed by modems.
Why Other Options Are Wrong:
Common Pitfalls:
Misspelling demodulator as “demodulater”. The correct engineering term is demodulator.
Final Answer:
Modulator Demodulator
Discussion & Comments