Question

The barrier layer capacitance of a point contact diode is_________

(a) 0.1pF to 1pF

(b) 5pF to 50pF

(c) 0.2pF to 2pF

(d) 0.008µF to 20µF

This question was posed to me by my college professor while I was bunking the class.

I'd like to ask this question from The Point Contact Diode in portion Semiconductor-Diode Characteristics of Electronic Devices & Circuits

Answer 1

Correct option is (a) 0.1pF to 1pF

The best I can explain: The barrier capacitance at the point is very low about 0.1pF to 1pF. The capacitance between the cat whisker and crystal is less compared to junction diode capacitance between both sides of the diode. For a general PN diode is 0.008µF to 20µF.