What size resistor is required to limit the current from a 12V battery 2 mA?

To calculate the resistance required to limit the current from a 12V battery to 2 mA, use Ohm's law, which states that the resistance of a circuit is equal to the voltage applied to the circuit divided by the current flowing through the circuit.

Formula: R = V / I

Given:

Voltage (V) = 12V

Current (I) = 2 mA = 0.002 A

Plug these values into the formula:

R = V / I

R = 12V / 0.002 A

R ≈ 6000 Ohms

Therefore, a 6000-ohm resistor is required to limit the current from a 12V battery to approximately 2 mA.