Which instrument is used to measure electric current? How should it be connected in a circuit?
Electric circuit
An electric circuit consists of a network of electric components connected in a closed loop. This loop is made using electrical wires and is powered by a source, like a battery, that enables the flow of current through the circuit.
These electrical components may be connected in series or parallel. Components in series connections receive the same amount of current but potential difference varies.
In parallel connection potential difference across each component remains constant but current varies through each branch of connection.
Explanation
An ammeter is a device used to measure current in an electric circuit. In series connection current through all components of the circuit is constant. Hence the device must be connected in series to measure the correct magnitude of current in a circuit.