Measuring Current in Electronic Circuits

To understand which tool is used to measure current, let's look at the function of each option provided:

• DSO (Digital Storage Oscilloscope): This instrument is primarily used to measure and display voltage signals as they change over time. It's useful for analyzing waveforms and timing, but it does not directly measure current.
• Ammeter: An ammeter is specifically designed to measure the electric current flowing through a point in a circuit. It must be connected in series with the component through which the current is to be measured.
• CRO (Cathode Ray Oscilloscope): Similar to a DSO, a CRO is also used to display and analyze voltage waveforms over time. It uses a cathode ray tube and is an older technology compared to DSO. It measures voltage, not current directly.
• Voltmeter: A voltmeter is used to measure the electric potential difference, or voltage, between two points in a circuit. It is connected in parallel across the component whose voltage is to be measured.

Based on the functions of these tools, the instrument specifically used to measure the current in any electronic circuit is the Ammeter.

Therefore, the correct tool for measuring electric current is the Ammeter.