What combination of both number and letter designation would be used to identify a diode and semiconductor device?

The correct combination used to identify a diode and semiconductor device is 1N. This designation specifically indicates a single junction diode. The "1" before the "N" signifies that it is a single device, while the "N" signifies that it is a semiconductor device, specifically a diode.

Diodes are commonly identified using this convention, where the numeral indicates the primary series of the device. For example, in the 1N series, you will find various component numbers that further define the characteristics of specific diodes.

In contrast, the 2N, 3N, and 4N designations are typically used to designate bipolar junction transistors (BJTs) or other semiconductor devices, where the numeral indicates different types or categories of these devices. Therefore, understanding these conventions helps in recognizing the specific functionalities and applications of diodes versus transistors in electronic circuits.