An n-p-n transistor has three leads A, B and C. Connecting B and C by moist fingers, A to the positive lead of an ammeter, and C to the negative lead of the ammeter, one finds large deflection. Then, A, B and C refer respectively to :
← JEE Main 2014 · 9 Apr · Shift 1
PhysicsSingle correct+4 / -1Question 30 of 90
JEE Main 2014 · 9 Apr · Shift 1, Physics question 30
Answer and worked solution
Official answer: A
In an analog meter used this way, the positive lead is connected to the negative terminal of the internal cell. So A is at the lower potential and C at the higher.
Linking B and C through the finger's resistance forward-biases the base-emitter junction (B above A). A large collector current then flows from C to A. So A is the emitter, B the base and C the collector.
Topics:Transistors