Question T6D04
From subelement T6 - T6D
Which of the following displays an electrical quantity as a numeric value?
Why is this correct?
A meter displays electrical quantities as numeric values, like volts, amperes, or ohms. The other choices don't display values: a potentiometer is a variable resistor used to adjust circuit parameters, a transistor is a switching/amplifying device, and a relay is an electrically-controlled switch. Only meters are designed specifically to measure and show numerical readings of electrical parameters.
Memory tip
Look for the word 'displays' in measurement questions — it's the key clue pointing to meters. Meters are the only components whose primary function is showing information to users, while other components perform circuit functions without displaying data.
Learn more
In amateur radio stations, meters are essential for monitoring transmitter performance, SWR readings, and power output levels. Digital multimeters display precise numerical values for troubleshooting circuits, while analog meters with moving needles provide quick visual references for tuning and adjustment. Understanding meter connections and readings helps ensure proper station operation and compliance with emission standards.
Think about it
Why do you think amateur radio operators often prefer analog meters for some measurements like SWR, even though digital meters provide more precise numerical readings?