When you turn on a battery-operated device, an electrical circuit is

When you turn on a battery-operated device, an electrical circuit is closed.

Explanation:

A circuit works, only when it is closed. When we turn on the battery-operated device, the circuit is closed & complete. Hence, the current will flow across the circuit.

Only closed circuits work (current flows through them). No current can flow in an open circuit.

Diagram attached:

that tool is called an altimeter which measures your altitude which can be used to tell which atmosphere you are currently in, including the stratosphere.

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