Simple diode circuit

[bharath]

Hi,
I have used simple resistor divider with the diode whose forward voltage drop is 0.6V as shown in figure. I am reading voltage in voltmeter as seen figure. Can anyone explain me why it is like this?

 

[Harald Kapp]

figure 1: the forward voltage drop of 0.7V is valid for currents of a few mA. Your voltmeter probably has an input resistance in the MegOhm range therefore the input current is very small which in turn leads to a smaller dropout voltage.
Put a 1kOhm resistor in parallel to th evoltmeter and observe the voltage drop.

figure 2: the diode is in reverse polarity, so no currenmt can flow. Therefore the voltmeter shows 0V.