Final answer:
To maintain constant current in the experiment, you are instructed to complete the circuit and allow the current to flow for about 30 seconds; the mA value is not provided and needs to be determined based on your specific setup and observed ammeter reading.
Step-by-step explanation:
In the context of this experiment, the specification about how long to keep the current constant is given in the procedure. You are instructed to complete the circuit and allow the current to flow for about 30 seconds. However, the exact milliampere (mA) value to maintain was not provided in the information you have included.
To calculate the current I using the equation I = ΔQ/Δt, we need the charge ΔQ that flows in a given time period Δt. For instance, if 0.1 Amps of current is sustained for a duration of 100 seconds, there's a total charge flow of 10 Coulombs. In terms of milliamperes, 0.1 Amps is equivalent to 100 milliamperes.
Remember to observe the ammeter reading during your experiment to ensure that you are maintaining the desired current level throughout the specified time frame.