A light emitting diode (LED) has a voltage drop of 2 V across it and passes a current of 10 mA. When it operates with a 6 V battery through a limiting resistor R, the value of .R is

The term LED is abbreviated as  'Light Emitting Diode'. It is forward biased p-n junction which emits spontaneous radiation. Current in the circuit= 10 mA = 10 x103 A and voltage in the circuit = 6 - 2= 4V From Ohm's law, V = IR∴R=VI=410×10−3=400 Ω