In p-n junction, avalanche current flows in circuit when biasing is
A. forward
B. reverse
C. zero
D. excess

Hint: The above problem can be resolved by using the concepts and applications of the semiconductors and the forward and reverse biasing applications. The avalanche is the condition in which the current flows through the junction diodes in an excessive amount. Moreover, avalanche's condition is valid for both kinds of materials, namely, the insulators and the semiconductors. Significantly, the avalanche can cause the failure of the junction diodes.

Complete step by step solution:
There are basic types of materials used for the analysis of the junction diodes. These materials include the semiconductor and the insulators. The Avalanche is the condition where the humongous amount of current is allowed to flow through these materials. And if insulators absorb this magnitude of current in a reasonable amount, then the material is known as an excellent insulator. Moreover, for the specific magnitude of the supply voltage, the reverse bias p junction will continuously increase.

Therefore, in the p-n junction, avalanche current flows in the circuit when biasing is reversed, and the option (B) is reversed.

Note: Try to understand the concept of the forward and the reverse bias. The forward biasing is that condition. The voltage is supplied to the junction diode, such that current flows through the diode and the voltage and current maintain the same phase. And in condition for reverse biasing, the supply voltage in the diode maintains an opposite phase. There are wide applications of the junction diodes including in the modern electronic circuits and appliances.