Question

An unknown transistor needs to be identified as a n-p-n or p-n-p type. A multimeter, with +ve and -ve terminals, is used to measure resistance between different terminals of transistor. If terminal 2 is the base of the transistor then which of the following is correct for a p-n-p transistor? 

(a) + ve terminal 2, -ve terminal 3, resistance low 

(b) + ve terminal 2, -ve terminal 1, resistance high 

(c) + ve terminal 1, -ve terminal 2, resistance high 

(d) + ve terminal 3, -ve terminal 2, resistance high

Answer 1

The correct option is (b) + ve terminal 2, -ve terminal 1, resistance high.

Explanation:

 p-n-p transistor: 

Positive at terminal 2 and negative at terminal 1 implies p-n junction is reverse biased and hence offers high resistance.