Question

The ratio of base – 1 resistance to the interbase resistance (RB1/RBB) is
1. known as intrinsic standoff ratio, and it is less than 1
2. known as intrinsic standoff ratio, and it is more than 1 
3. known as extrinsic standoff ratio, and it is less than 1
4. known as extrinsic standoff ratio, and it is more than 1 

Answer 1

Correct Answer - Option 1 : known as intrinsic standoff ratio, and it is less than 1

Concept:

• For a unijunction transistor (UJT), the resistive ratio of R_B1 to R_BB is called the intrinsic stand-off ratio and is given the Greek symbol: η.
• Typical standard values of η range from 0.5 to 0.8 for most common UJT’s.
• It is also defined as the ratio of the standoff voltage to the power supply voltage, where the standoff voltage is the voltage needed to fire electrons to unijunction transistors emitter.