An LED requires a current of to operate safely and has a forward voltage drop of

PHYSICS · Multi-part · CBSE · Physics · Electricity · Electricity

Problem

An LED requires a current of 20 mA20\,\text{mA} to operate safely and has a forward voltage drop of 2.0 V2.0\,\text{V}. It is to be powered by a 9.0 V9.0\,\text{V} battery with negligible internal resistance. (i) Determine the value of the series resistor that must be connected with the LED. (ii) Calculate the power dissipated in this resistor when the LED is operating.

Related theory

Browse the problem library