In this scenario, we have an electric circuit consisting of a cell, an ammeter, and a nichrome wire of length l. The question is asking what happens to the ammeter reading if the length of the wire is reduced to half (l/2).

Let`s examine each option to understand the possible outcomes:

Option 1: If the length of the wire is decreased to half, the resistance of the wire would decrease. According to Ohm`s Law (V = IR), if the resistance decreases, then the current (I) would increase. Consequently, the ammeter reading would increase, not decrease. Therefore, option 1 is incorrect.

Option 2: This is the correct option. When the length of the wire is halved, the resistance of the wire is halved as well. As a result, the current flowing through the circuit doubles. Since the ammeter measures the current, the reading on the ammeter would also double.

Option 3: Similar to option 1, if the resistance decreases, the current increases, and the ammeter reading would increase, not decrease. Therefore, option 3 is incorrect.

Option 4: Since the length of the wire affects its resistance and resistance affects current, if the length of the wire is