Identify the circuit (Figure 12.3) in which the electrical components have been properly connected

Hint: Check the connections of the Voltmeter and Ammeter.

Step 1: Checking if the Voltmeter is connected in parallel and Ammeter is connected in series.   

In circuits $(i)$ and $(iii)$, Voltmeter is connected in series. In circuit $(iii)$ the ammeter is connected in parallel. In circuits $(i)$ and $(iii)$, connections are not proper. 

In circuits $(ii)$ and $(iv)$, the Voltmeter and Ammeter are connected in parallel and series respectively. 

Step 2: Checking if the terminals are connected properly.   

In circuit $(iv)$, the positive terminal of the ammeter is connected with the negative terminal of the cell. Hence it is not proper. 

Whereas in circuit $(ii)$, all the terminals are properly connected. Therefore option $(B)$ is the correct option.