#### CBSE NOTES CLASS 12 PHYSICS

#### CHAPTER 14 SEMICONDUCTORS

**Digital electronics**

**Analog signal**

The signal (current or voltage) in the form of continuous, time-varying voltage or current is called analog signal.

**Digital signal**

A signal with discrete values of voltages or current is called digital signal.

If there are only two discrete values possible, we use binary numbers to represent such signals. A binary number has only two digits ‘0’ (say, 0V, for low) and ‘1’ (say, 5V, for high).