Q.Write a short note on noise.

Noise is the unwanted electrical energy that limits how well a communication system can recover a signal.

[!ANSWER]

Noise is any unwanted electrical energy that interferes with the correct reception of the wanted signal; it is random, may be internal or external, can be minimized but not eliminated, and is measured using SNR, noise figure and noise temperature.

[!TLDR]

Noise is unwanted, random electrical energy that degrades a signal; it can be reduced but never fully removed.

Noise is any unwanted electrical energy that tends to interfere with the easy and correct reception and reproduction of the wanted signal. Its main features are:

• It is random in nature.
• It may be internal (generated within the system) or external (from outside sources).
• It can be minimized but not completely eliminated.
• Its effect is measured using parameters such as the signal-to-noise ratio (SNR), the noise figure (NF) and the noise temperature.

Because noise sets the limit on the smallest signal a receiver can handle, keeping it low is central to good communication-system design.

[!ANSWER]

Noise is unwanted, random electrical energy — internal or external — that interferes with correct reception of the wanted signal; it can be minimized but not eliminated and is quantified by SNR, noise figure and noise temperature.