pn diode numericals

A diode is

The PN junction diode is used as

A pn junction diode in which light in allowed to fall in its junction is

When the voltage drop across a p.n junction diode is increased from 0.65V to 0.70V , the change in the diode current is 5mA . What is the dynamic resistance of the diode?

When a voltage drop across a pn junction diode is increased from 0.70 V to 0.71V, the change in the diode current is 10 mA .What is the dynamic resistance of diode ?

PN -junction diode works as a insulator, if connected