In this section of Electronic Devices and Circuits.It contain Active Filters MCQs (Multiple Choice Questions Answers).All the MCQs (Multiple Choice Question Answers) requires in depth reading of Electronic Devices and Circuits Subject as the hardness level of MCQs have been kept to advance level.These Sets of Questions are very helpful in Preparing for various Competitive Exams and University level Exams.

**This Section Covers below lists of topics :**

- Ideal Responses MCQs
- Approximate Response MCQs
- Passive Filters MCQs
- First-Order stages MCQs
- VCVS Unity-Gain Second Order Low-Pass Filters MCQs
- Higher-Order Filters MCQs
- VCVS Equal-component Low-Pass Filters MCQs
- VCVS High-Pass Filters MCQs
- MFB Bandpass Filters MCQs
- Bandstop Filters MCQs
- All-Pass Filters MCQs
- Biquadratic and State-Variable Filters MCQs

**Practice it now to sharpen your concept.**

#### 1. The region between the passband and the stopband is called the

- Attenuation
- Center
- Transition
- Ripple

#### 2. The center frequency of a bandpass filter is always equal to

- The bandwidth
- Geometric average of the cutoff frequencies
- Bandwidth divided by Q
- 3-dB frequency

#### 3. The Q of a narrowband filter is always

- small
- equal to BW divided by f0
- less than 1
- greater than 1

#### 4. A bandstop filter is sometimes called a

- Snubber
- Phase shifter
- Notch filter
- Time-delay circuit

#### 5. The all-pass filter has

- No passband
- One stopband
- the same gain at all frequencies
- a fast roll-off above cutoff

#### 6. The approximation with a maximally-flat passband is

- Chebyshev
- Inverse Chebyshev
- Elliptic
- Bessel

#### 7. The approximation with a rippled passband is

- Butterworth
- Inverse Chebyshev
- Elliptic
- Bessel

#### 8. The approximation that distorts digital signals the least is the

- Butterworth
- Chebyshev
- Elliptic
- Bessel

#### 9. If a filter has six second order stages and one first-order stage, the order is

- 2
- 6
- 7
- 13

#### 10. If a Butterworth filter has 9 second-order stages, its roll-off rate is

- 20 dB per decade
- 40 dB per decade
- 180 dB per decade
- 360 dB per decade

#### 11. If n = 10, the approximation with the fastest roll-off in the transition region is

- Butterworth
- Chebyshev
- Inverse Chebyshev
- Elliptic

#### 12. The elliptic approximation has a

- Slow roll-off rate compared to the Cauer
- Rippled stopband
- Maximally-flat passband
- Monotonic stopband

#### 13. Linear phase shift is equivalent to

- Q = 0.707
- Maximally-flat stopband
- Constant time delay
- Rippled passband

#### 14. The filter with the slowest roll-off rate is the

- Butterworth
- Chebyshev
- Elliptic
- Bessel

#### 15. A first-order active-filter stage has

- One capacitor
- Two op amps
- Three resistors
- a high Q

#### 16. A first-order stage cannot have a

- Butterworth response
- Chebyshev response
- Maximally-flat passband
- Rolloff rate of 20 dB per decade

#### 17. Sallen-Key filters are also called

- VCVS filters
- MFB filters
- Biquadratic filters
- State-variable filters

#### 18. To build a 10th-order filter, we should cascade

- 10 first-stage stages
- 5 second-order stages
- 3 third-order stages
- 2 fourth-order stages

#### 19. To get a Butterworth response with an 8th-order filter, the stages need to have

- Equal Q’s
- Unequal center frequencies
- Inductors
- Staggered Q’s

#### 20. To get a Chebyshev response with a 12th-order filter, the stages need to have

- Equal Q’s
- Equal center frequencies
- Staggered bandwidths
- Staggered center frequencies and Q’s

#### 21. The Q of a Sallen-Key second-order stage depends on the

- Voltage gain
- Center frequency
- Bandwidth
- GBW of the op amp

#### 22. With Sallen-Key high-pass filters, the pole frequency must be

- Added to the K values
- Subtracted from the K values
- Multiplied by the K values
- Divided by the K values

#### 23. If BW increases, the

- Center frequency decreases
- Q decreases
- Roll-off rate increases
- Ripples appear in the stopband

#### 24. When Q is greater than 1, a bandpass filter should be built with

- Low-pass and high-pass stages
- MFB stages
- Notch stages
- All-pass stages

#### 25. The all-pass filter is used when

- High roll-off rates are needed
- Phase shift is important
- A maximally-flat passband is needed
- A rippled stopband is important

#### 26. A second-order all-pass filter can vary the output phase from

- 90 degrees to -90 degrees
- 0 degrees to -180 degrees
- 0 degrees to -360 degrees
- 0 degrees to -720 degrees

#### 27. The all-pass filter is sometimes called a

- Tow-Thomas filter
- Delay equalizer
- KHN filter
- State-variable filter

#### 28. The biquadratic filter

- Has low component sensitivity
- Uses three or more op amps
- Is also called Tow-Thomas filter
- All of the above

#### 29. The state-variable filter

- Has a low-pass, high-pass, and bandpass output
- Is difficult to tune
- Has high component sensitivity
- Uses less than three op amps

#### 30. If GBW is limited, the Q of the stage will

- Remain the same
- Double
- Decrease
- Increase

#### 31. To correct for limited GBW, a designer may use

- A constant time delay
- Predistortion
- Linear phase shift
- A rippled passband