An ammeter is an instrument used to measure the current flowing through a circuit. It is designed to measure the exact current passing through the load. Let's explore why an ammeter is always connected in series with the load:

1. Function of an Ammeter: The main purpose of an ammeter is to measure the current flowing in a circuit. To achieve this accurately, it needs to be part of the circuit path through which the current flows.
2. Series Connection Requirement: An ammeter must carry the same current as the load for correct measurement, which can only be ensured by connecting it in series with the load. When connected in series, both the ammeter and load share the same current.
3. Low Resistance of Ammeter: Ammeters are designed with very low internal resistance so that they don't add significant resistance to the circuit, which ensures that the original current flowing through the circuit remains largely unaffected by their presence.
4. Eliminating Other Options:
   • The option indicating it stores charge before displaying the reading is incorrect because an ammeter does not store charge.
   • An ammeter does not increase the supply voltage across the load as it is designed to measure current, not influence voltage.
   • The option suggesting it has very high resistance is incorrect as such a property would impede the accurate measurement of the current by limiting it significantly.

Hence, the correct answer is that an ammeter must carry the same current as the load for correct measurement. This ensures accuracy and integrity of the current measurement.