To measure the current accurately in an electrical circuit, an ammeter should be connected in series with the load. This is because an ammeter is designed to measure the flow of current through it, and placing it in series ensures that the same current flows through both the ammeter and the load.

1. Understanding Current Measurement: A circuit's current is the flow of electric charge. The purpose of an ammeter is to measure this flow. To achieve an accurate measurement, the ammeter must be in the path of the electrical current it is measuring.
2. Series Connection Explained: By connecting the ammeter in series, it becomes a part of the circuit's current path. This allows the entire current, which flows through the circuit, to pass through the ammeter, providing an accurate measurement.
3. Reasons for Avoiding Other Connections:
   • Parallel with a Resistor: If an ammeter is connected in parallel with a resistor, it would cause a short circuit across the resistor, because ammeters have very low resistance. This setup is not only dangerous but also incorrect for measurement purposes.
   • Parallel with the Load: Placing an ammeter in parallel with the load would again create a short circuit due to the ammeter's low resistance. Since some of the current would bypass the load and flow through the ammeter, this would not provide an accurate measurement of the current through the load.
   • Across the Supply Terminals: Connecting an ammeter directly across the supply terminals would likely damage the ammeter due to its low resistance, effectively short-circuiting the supply.
4. Conclusion: Therefore, the correct method to measure current with an ammeter is to connect it in series with the load. This ensures that the ammeter records the true current flowing through the circuit.