Which symbol is commonly used to denote the ammeter in circuit diagrams?

Which symbol is commonly used to denote the ammeter in circuit diagrams?

• A. A circle with the letter A inside
• B. A circle with the letter V inside
• C. A circle with the letter I inside
• D. A circle with the letters AM inside

Answer: (A)

Ammeters measure electrical current, and the symbol used in circuit diagrams to represent an ammeter is a circle with the letter A inside, standing for Ampere. This makes it immediately clear what is being measured. In contrast, a voltmeter uses a circle with a V inside and is connected in parallel to measure voltage without loading the circuit too much. The circle with I inside isn’t a standard instrument symbol in basic schematics, and AM inside doesn’t follow the conventional notation. Since an ammeter should measure the current flowing through a path, it is placed in series and is designed to have very low resistance to avoid significantly altering the current.

Ammeters measure electrical current, and the symbol used in circuit diagrams to represent an ammeter is a circle with the letter A inside, standing for Ampere. This makes it immediately clear what is being measured. In contrast, a voltmeter uses a circle with a V inside and is connected in parallel to measure voltage without loading the circuit too much. The circle with I inside isn’t a standard instrument symbol in basic schematics, and AM inside doesn’t follow the conventional notation. Since an ammeter should measure the current flowing through a path, it is placed in series and is designed to have very low resistance to avoid significantly altering the current.