A working transitor with its three legs marked `P, Q and R` is tested using a multimeter No conduction is found between `P, Q `by connecting the common (negative) terminal of the multimeter to `R`and the other (positive) terminal to or `Q` some resistance is seen on the multimeter . Which of the following is true for the transistor ?

Options

A. it is a pnp transistor with R as collector
B. it is a pnp transistor with R as emitter
C. it is an npn transistor with R as collector
D. it is an npn transistor with R as base.

Answer

D

Explanation

`I=n_(e)Av_(d)`
`(I_(e))/(I_(h))=(n_(e)xx(v_(d))_(e))/(n_(h)xx(v_(d))_(h))`
Here, `(n_(e))/(n_(h))=(7)/(5),(I_(e))/(I_(h))=(7)/(4)`
`(7)/(4)=(7)/(5)xx((v_(d))_(e))/((v_(d))_(h))`
`implies((v_(d))_(e))/((v_(d))_(h))=(5)/(7)xx(7)/(4)=(5)/(4)`.