Hi Youtube, today I will show you a beauty about NDD's analysis test in general electronics. So, if you have an 3 volt battery, you are connected to a 3-12 LED. That will come out. No problem. But, what if you are giving 5 volt possible to an LED? You will destroy the LED in the process. So, that is not the picture of the LED blowing up. You will be like, ok. Ok, like this. So, in order to keep the LED safe from blowing up, you have to use air resistance. But, you have to find the value of the resistor. So, we have to learn two things, where it is. Whenever I need to connect to a circuit, it consumes a voltage. It is called forward voltage. For more, most of the LED will be 2 volt. And, the maximum safe current for a LED, I current is 20 milliampere. 20 into 10 to the power of 2 minus 3 amps. So, we have to take 2 of these in the account. This is the resistor for the LED. Suppose, I am having a 5 volt for supply. This 5 volt will be given, distributed across R and across LED. So, LED is having a 2 volt. And, the resistor will take some of the voltage. It is called VR. Water volt energy is given, it will be taken with a resistor and the LED. So, battery voltage 5 volt is equal to VR plus 2. We know that by omelette voltage is equal to current into resistance. We know it is 2 here, it is 5 here and also VR. VR is equal to I into R. This I is for the LED. So, we are putting LED voltage, LED current is 20 milliampere. It is equal to 10 to 10 to the power minus 3 into R. This is substitute here. So, we like 5 is equal to R into power 0.20 into, sorry, R into power 0.20 plus 2. So, R is equal to 3 by power 0.20 by 2. This is R into 2 equal to 1 plus 3 ohms. So, we can put a higher value like 2 to 10 d ohms. So, we have to put an first drop 2 to 10 d ohms. So, if you are using an angle battery, then again in the same equation, you have to just change the values. And, you can find the value resistor. Thank you.