Forward and Reverse Bias — Prelims Questions

A silicon p-n junction diode has a barrier potential of $0.7,\text{V}$. If it is forward biased with an external voltage of $0.5,\text{V}$, what is the effective potential barrier across the junction?

Which of the following statements is TRUE regarding a p-n junction under reverse bias?

A germanium diode has a cut-in voltage of $0.3,\text{V}$. If it is connected in series with a $100,Omega$ resistor and a $1.0,\text{V}$ battery (forward biased), what is the approximate current flowing through the circuit?

A p-n junction diode is connected in a circuit as shown. The potential at point A is $+5,\text{V}$ and at point B is $+2,\text{V}$. What is the bias condition of the diode?

The reverse saturation current of a p-n junction diode is $10,\text{nA}$ at $27^circ\text{C}$. Assuming the reverse saturation current doubles for every $10^circ\text{C}$ rise in temperature, what will be the approximate reverse saturation current at $47^circ\text{C}$?

Which of the following conditions is necessary for a p-n junction diode to emit light (as in an LED)?