Question

Which of the following statements is correct?

If the channel bandwidth doubles, the S/N ratio becomes
1. double of the former S/N ratio
2. square root of the former S/N ratio
3. half of the former S/N ratio
4. none of these

Answer 1

Correct Answer - Option 3 : half of the former S/N ratio

The noise in the system is directly proportional to the bandwidth, i.e.

Noise ∝ Bandwidth

Signal to noise ratio is defined as:

\(SNR=\frac{S}{N}=\frac{Signal~Power}{Noise~Power}\)

Observations:

1) As the bandwidth increases, the noise in the system will increase.

2) As the noise in the system increases, the S/N ratio will decrease.

∴  If Bandwidth is doubled then, S/N ratio will be halved.