How should an ammeter be connected to measure current in a circuit?

How should an ammeter be connected to measure current in a circuit?

• A. In series with the load
• B. In parallel with the source
• C. Across the load
• D. Across the source

Answer: (A)

To measure current, the ammeter must be placed in series with the load. Current is the same through all components in a single path, so inserting the meter in the path of the circuit ensures the entire current flows through it, giving an accurate reading. The ammeter is designed with very low resistance so it doesn’t appreciably affect the circuit voltage or current. If placed in parallel with the load, the meter would create an alternate path of low resistance, drawing a large portion of the current and giving an incorrect reading or potentially causing a short. If placed across the source, it would effectively short the supply through the meter’s low resistance, which is dangerous and could damage components.

To measure current, the ammeter must be placed in series with the load. Current is the same through all components in a single path, so inserting the meter in the path of the circuit ensures the entire current flows through it, giving an accurate reading. The ammeter is designed with very low resistance so it doesn’t appreciably affect the circuit voltage or current. If placed in parallel with the load, the meter would create an alternate path of low resistance, drawing a large portion of the current and giving an incorrect reading or potentially causing a short. If placed across the source, it would effectively short the supply through the meter’s low resistance, which is dangerous and could damage components.