regarding LED voltage and current

[mdkmahesh]

What are the minimum voltage and current values required for glowing a red LED? I seen that 1.7v is the nominal voltage,what is meant by nominal in that case?

 

[taroot]

If LED is 3mm(normal through hole LED) then 3 to 4v needed with a current of 10 to 15mA.

 

[akshay985]

1.2 to 1.7v will drop accross the led and it draws about 5mA current

 

[alexan_e]

Please take a look at this tutorial
Light Emitting Diodes (LEDs)

You will also see a table listing the average Vf for each led color

Alex

 

[mdkmahesh]

If the voltage is less than 1.7V,whether the LED will glow or not? what are the minimum and maximum values of current for red LED?