How should ammeters be used to take measurements in a circuit?

• A. Connected in parallel with the circuit
• B. Connected in series with the circuit
• C. Connected to the ground only
• D. Connected at the power source

Answer: (B)

Ammeters are designed to measure the current flowing through a circuit. To accurately measure this current without altering the circuit significantly, they must be connected in series. This series connection allows the ammeter to become a part of the circuit, ensuring that all the current flowing through the circuit also flows through the ammeter itself.

When placed in series, the ammeter provides a direct pathway for current and measures it effectively without creating a separate branch that could lead to incorrect readings. Using an ammeter in this way helps maintain the integrity and functionality of the circuit being tested.

Connecting an ammeter in parallel, connecting it only to the ground, or connecting it solely at the power source would not provide accurate current measurement and could potentially damage the meter or create dangerous conditions within the circuit. Therefore, the correct approach is to ensure the ammeter is placed in series with the load or component whose current you wish to measure.