### Analog Filters

1. Compare analog filters with digital filters.
2. Operating characteristics of simple analog filters, such as RC, LC, RL, RLC, Chebychev filters

In order to eliminate the unwanted interference that accompanies a signal, a filter is needed.

##### Classification of filters:
• Low pass filters
• High pass filters
• Band-pass filters
• Band-reject filters
##### Classification of filters:
• Continuous time
• Discrete time
##### Classification of filters:
• Passive filters
• Active filters

### Solved Example:

#### 9940-01

Find the cut-off frequency for an RC low pass filter of R = 8.2 $\Omega$ and C = 0.0033 $\mu$F. (UPPSC AE Electrical Dec 2020)

### Solved Example:

#### 9940-02

A simple low pass RC filter having a cut-off frequency of 1 kHz is connected to a constant ac source of 10 V. Calculate C if R = 10 k$\Omega$ (CIL MT Electrical: 2020)

### Solved Example:

#### 9940-03

$G(s) = \dfrac{1}{(1 + sRC)}$ in a RC network represents _______: (BSNL JE (TTA) Sep 2016 Shift I)

### Solved Example:

#### 9940-04

For attenuation of high frequencies, we should use: (EKT Computer Science Paper II : 02/2015)

### Solved Example:

#### 9940-05

Consider a low-pass filter module with a pass-band ripple of $\delta$ in the gain magnitude. If M such identical modules are cascaded, ignoring the loading effects, the pass-band ripple of the cascade is: (GATE IN 2015)