Question

Technician A says that an Ammeter must be connected in series with the circuit to measure current. Technician B says that if an ammeter is hooked up to a circuit incorrectly it can blow the fuse in the meter. Who is correct?

1) A only
2) only
3) Both A and B
4) Neither A or B

Answer 1

Both Technician A and B are correct; an ammeter is connected in series for accurate current measurement, and a wrongly connected ammeter can blow its internal fuse.

Step-by-step explanation:

Technician A is correct when stating that an ammeter must be connected in series with the circuit to measure current. This is because all the current in the circuit must flow through the meter, ensuring an accurate measurement. In reference to Figure 21.31, the ammeter (symbol A) is shown placed in series, allowing it to measure the current.

Technician B is also correct in saying that if an ammeter is hooked up incorrectly, it can blow the fuse in the meter. Ammeters typically contain a fuse to protect against damage from excessively high currents. Due to their very low resistance, they are vulnerable to high current if connected improperly, for example, in parallel or across a high voltage source.

Therefore, the answer to the student's question is (3) Both A and B.