1. The problem statement, all variables and given/known data All LEDs in the following circuit are identical. Each LED has a switch on voltage of 2V and draws a current of 20mA for optimal light production. Determine the resistance of Rl that gives optimum operation for all LEDs. 2. Relevant equations Ohms Law V=IR 3. The attempt at a solution becuase the LEDs are connected in parallel I calculated the voltage for Rl to be 9-2 =7V then divided that by 20mA which gave me 350ohms, which is incorrect.