Question

Given below are two statements : Statement I : PN junction diodes can be used to function as transistor, simply by connecting two diodes, back to back, which acts as the base terminal. Statement II : In the study of transistor, the amplification factor β indicates ratio of the collector current to the base current. In the light of the above statements, choose the correct answer.

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is true but Statement II is false
• D. Statement I is false but Statement II is true

Hint:

For a transistor to work, the base must be extremely thin and lightly doped so that charge carriers can diffuse from the emitter to the collector.

Answer 1

The Correct Option is D

Step 1: Statement I is false. A transistor is a single crystal with three regions. Back-to-back diodes have two separate depletion layers and no interaction between the "emitter" and "collector" through a shared thin base.
Step 2: Statement II is true. $\beta$ (Current gain in CE mode) $= I_C / I_B$.