Experiment No. 2

Diodes

Exercise : Using a multimeter , identify the anode and cathode of the diode and the LED.

Explain how you could identify the cathode without a multimeter.

On the diode there is a silver mark painted on one end which indicates the cathode side of the diode.

Table 1 : Data sheet of 1N4OO7 is as follows

Exercise : For Vs = 5V, R= 1k ohms, D= 1N4007 build the following circuit on a bradboard.

Calculate first the value of the current flowing through the diode, now measure and check your answer?

Calculated Value

I = V/R

5/1000 = 0.005A therefore the answer is 5mA

Measured Value

The measured value of the diode is 4.9mA

Is the reading as you expected; explain why or why not?

According to the Ohms Law A = V/R the answer I calculated and measured with the Ohmmeter is almost equal to each other i.e 5mA and 4.9mA.

Calculate the voltage drop across the diode, now measure and check your answer?

Calculated Value

0.576V

Measured Value

0.688V

Using the data sheet given in Table 1 above,

What is the maximum vaulue of the current that can flow through the given diode?

Maximum value of current is 1.0Amps at 75'c.

For R= 1K ohms. What is the maximum value of Vs so that the diode operates in a safe region?

The maximum value of Vs at which the diode will be in safe region is 1000Volts.

Replace the diode by an LED & calculate the current, then measure and check your answer?

Calculated Value

I = V/R

5/1000 = 0.005A therefore the answer is 5mA

Measured Value

The measured value of the LED is 2.19mA

What do you observe ? Explain briefly.

After carrying out the experiment I found out that the LED and the diode they both use slightly differrent amount of amps through the circuit even when you replace them with each other.