In the experiment of Ohm's law with nichrome wire, as the number of cells increases:

Ohm's law, states that the current (I) in a circuit is directly proportional to the voltage (V) across the circuit when the resistance (R) remains constant. 

Mathematically, Ohm's law is represented as:

I = V / R

When you increase the number of cells or voltage sources in the circuit, the voltage (V) also increases. If the resistance of the nichrome wire remains constant, the increase in voltage will lead to an increase in current (I).