The voltage drop across an LED is 2 Volts. It is connected to a 5 volt power supply with a resistor, as shown. What resistor value should be used to set the LED current to 4 mA?

The voltage drop across an LED is 2 Volts It is connected to a 5 volt power supply with a resistor as shown What resistor value should be used to set the LED cu class=

Respuesta :

Answer:

Explanation:

The voltage drop across an LED is 2 Volts. It is connected to a 5 volt power supply

so voltage at resistor = 5-2 = 3V

by ohms' law, V=IR n current at 4mA or 0.004A

R = 3/0.004 = 750 ohms