Question T7D04
From subelement T7 - T7D
Which instrument is used to measure electric current?
Why is this correct?
An ammeter is specifically designed to measure electric current (the flow of electrons). The retrieved context clearly states 'The ammeter function of a multimeter is used to measure current.' An ohmmeter measures resistance, a voltmeter measures voltage (electric potential), and an electrometer measures electric charge. Each instrument has a distinct purpose: ammeters for current (amperes), voltmeters for voltage (volts), and ohmmeters for resistance (ohms).
Memory tip
Remember the pattern: instrument names often reveal their function. 'Ammeter' contains 'amp' (for amperes, the unit of current), 'voltmeter' contains 'volt' (the unit of voltage), and 'ohmmeter' contains 'ohm' (the unit of resistance). This naming convention helps distinguish measurement tools.
Learn more
In practical amateur radio operation, current measurement is crucial for monitoring power consumption and ensuring your transmitter operates within safe limits. When troubleshooting circuits, ammeters connect in series with the circuit path so all current flows through the meter, allowing accurate measurement of electron flow. Understanding current flow helps determine if your equipment draws excessive power or if circuit components are functioning properly.
Think about it
Why do you think an ammeter must be connected in series with a circuit rather than in parallel like a voltmeter?