Consider a box with three terminals on top of it:
Three components namely, two germanium diodes and one resistor are connected across these three terminals in some arrangement. A student performs an experiment in which any two of these three terminals are connected in the circuit shown in the figure (b).
The student obtains graphs of current-voltage characteristics for an unknown combination of components between the two terminals connected in the circuit.
The graphs are
(i) when A is positive and B is negative
(ii) when A is negative and B is positive
(iii) When B is negative and C is positive
(iv) When B is positive and C is negative
(v) When A is positive and C is negative
(vi) When A is negative and C is positive
From these graphs of current-voltage characteristic shown in the figures, determine the arrangement of components between A, B and C.
(a) A is connected to the n-side of the PN junction and B is connected to the top-side of pn junction.
(b) 0.7 V is the knee voltage.
(c) Pn junction is connected to C and n-side of pn junction to B and knee voltage is 0.7 V.
(d) The above conditions explains the connection of pn-junction along I and II with the resistance.