Question

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

• A. It is a n-p-n transistor with R as base
• B. It is a p-n-p transistor with R as collector
• C. It is a p-n-p transistor with R as emitter
• D. It is a n-p-n transistor with R as collector

Answer 1

Answer: (A)

Since no conduction is found when the multimeter is connected across P and Q it means either both P and Q are n-type or p-type. So, it means R is base. When R is connected to the common terminal and conduction is seen when another terminal is connected to P and Q, so it means transistor is in n-p-n configuration with R as the base.