Deep Dive: T7D07
The correct answer is C: Voltage and resistance. A multimeter can make voltage and resistance measurements. Multimeters (also called VOMs - Volt-Ohm-Milliammeters) are versatile instruments that combine the functions of voltmeters, ohmmeters, and ammeters. They can measure DC voltage, AC voltage, resistance, and often current. For amateur radio operators, multimeters are the most common test instrument, used for virtually all basic electrical measurements. Understanding what a multimeter can measure helps when selecting test equipment and planning troubleshooting procedures.
Why Other Answers Are Wrong
Option A: Incorrect. Signal strength and noise are RF measurements typically made with specialized instruments like S-meters, spectrum analyzers, or noise figure meters, not multimeters. Option B: Incorrect. Impedance and reactance are AC/RF measurements requiring specialized instruments like impedance analyzers or antenna analyzers, not basic multimeters. Option D: Incorrect. Since A and B are wrong, 'all of the above' cannot be correct. Multimeters measure voltage and resistance, not RF parameters.
Exam Tip
Multimeter = measures voltage and resistance. Think 'M'ultimeter = 'M'easures 'V'oltage and 'R'esistance. Signal strength, noise, impedance, and reactance require specialized RF instruments, not multimeters.
Memory Aid
Multimeter = measures Voltage and Resistance. Think 'M'ultimeter = 'M'easures 'V'oltage and 'R'esistance. Basic electrical measurements, not RF parameters.
Real-World Example
Your multimeter can measure the voltage of your power supply (13.8 volts DC) and the resistance of a resistor (1000 ohms). However, it cannot measure the signal strength of an RF signal or the impedance of an antenna - those require specialized RF measurement instruments. Multimeters are for basic DC/AC electrical measurements.
Source & Coverage
Question Pool: 2022-2026 Question Pool
Subelement: T7D
Reference: 2022-2026 Question Pool · T7 - Practical circuits
Key Concepts
Verified Content
Question from the official FCC Technician Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the T7D topic.