Final answer:
A circuit diagram for studying IV characteristics of a diode in forward bias shows the p-type connected to the positive terminal and the n-type to the negative terminal. The threshold voltage, typically around 0.7 V for silicon diodes, marks the beginning of significant current flow.
Step-by-step explanation:
To study the IV characteristics of a p-n junction diode in the conducting mode, you would typically set up a circuit with the diode in forward bias by connecting the p-type material to the positive terminal of a battery and the n-type material to the negative terminal. This arrangement allows for the study of how current flows through the diode at differing voltage levels. The threshold voltage is marked on the graph as the point where the diode begins to conduct significantly. It is often close to 0.7 V for silicon diodes.
The significance of this voltage is that it represents the minimum potential difference at which the diode starts to allow current to flow through it effectively, indicating the overcoming of the potential barrier due to the depletion region at the p-n junction.