Filter Selectivity Quiz

Play an AI-generated podcast conversation about this lesson

What is the main characteristic of ideal filters in terms of output voltage?

Decreases gradually at the cut-off frequency

Increases sharply at the cut-off frequency

Stops completely at the cut-off frequency (correct)

Has no specific pattern at the cut-off frequency

Why are highly selective and steep response curves impossible to achieve in practical filters?

The use of techniques that limit steepness

Design limitations and practical constraints (correct)

Because of gradual attenuation with frequency

Due to the use of special components

At what frequencies does the output voltage decrease gradually in a low-pass filter?

At frequencies above the cut-off frequency (correct)

At a constant rate with frequency

At high frequencies after the cut-off

At low frequencies before the cut-off

What configuration does an RC low-pass filter use?

Resistor in series with capacitor Signup and view all the answers

What happens to attenuation in a high-pass filter as frequency increases?

Attenuation decreases gradually Signup and view all the answers

Why can't practical filters achieve ideal response curves?

Design limitations and constraints Signup and view all the answers

What happens to the capacitive reactance (XC) as the frequency increases in an RC high-pass filter?

XC decreases Signup and view all the answers

Which statement best describes the behavior of an RL high-pass filter at frequencies below the cut-off frequency?

Most of the generator voltage will be across the resistor and very little voltage will appear across the output inductor. Signup and view all the answers

What happens to the inductive reactance (XL) as the frequency increases in an RL high-pass filter?

XL increases Signup and view all the answers

What is the output voltage of an RC high-pass filter at the cut-off frequency (fCO) relative to the maximum applied voltage?

70.7% Signup and view all the answers

Which statement best describes the performance of RC and RL high-pass filters?

The performance of RC and RL high-pass filters is the same. Signup and view all the answers

At frequencies below the cut-off frequency in an RC high-pass filter, what happens to the voltage across the capacitor?

The voltage across the capacitor is very high. Signup and view all the answers

What happens to the voltage division ratio when the supply frequency changes?

It changes, causing the output voltage to vary Signup and view all the answers

How can filters be designed to pass or eliminate desired frequencies?

By adjusting the resistance and capacitance values of the voltage divider Signup and view all the answers

What condition is known as resonance in an LCR circuit?

When inductive reactance equals capacitive reactance Signup and view all the answers

What is the characteristic of a resonant circuit?

It is totally resistive Signup and view all the answers

How does the inductive reactance change with an increase in frequency?

It increases Signup and view all the answers

How does the capacitive reactance change with a decrease in frequency?

It increases Signup and view all the answers

What type of filter is described in the text?

Low-pass filter Signup and view all the answers

How does the output voltage of a voltage divider compare to the input voltage in an AC circuit?

The output voltage is always less than the input voltage Signup and view all the answers

How does the inductive reactance (XL) vary with frequency?

XL is proportional to frequency Signup and view all the answers

How does the capacitive reactance (XC) vary with frequency?

XC is inversely proportional to frequency Signup and view all the answers

In an RL low-pass filter, what happens to the voltage across the inductor as frequency increases?

The voltage across the inductor increases Signup and view all the answers

What is the primary purpose of an RL low-pass filter?

To attenuate high frequencies while allowing low frequencies to pass Signup and view all the answers

What is the primary ability of an LCR circuit?

To separate frequencies Signup and view all the answers

In a series resonant circuit at resonance, what is the characteristic of the impedance?

Resistive and low value Signup and view all the answers

In a parallel resonant circuit (tank circuit) at resonance, what is the characteristic of the impedance?

Resistive and high value Signup and view all the answers

What do series LC resonant circuits offer regarding current flow?

Minimum opposition at resonant frequency, maximum opposition at other frequencies Signup and view all the answers

What do parallel LC resonant circuits offer regarding current flow?

Maximum opposition at resonant frequency, minimum opposition at other frequencies Signup and view all the answers

What is the primary application of resonant circuits mentioned in the text?

Filters Signup and view all the answers

What is the main cause of copper losses in a transformer?

Resistance of the primary and secondary windings Signup and view all the answers

Which type of transformer typically has the highest efficiency?

Large electrical utility distribution transformers Signup and view all the answers

What is the main purpose of minimizing losses in a transformer?

To reduce the undesirable conversion of electrical energy into heat energy Signup and view all the answers

What type of loss is caused by the resistance of the transformer windings?

Copper loss Signup and view all the answers

What is the main reason large power transformers have higher efficiency compared to smaller transformers?

They have lower eddy current and hysteresis losses Signup and view all the answers

What is the primary cause of heat generation in a transformer?

All of the above Signup and view all the answers

What is the total circuit resistance when a 24 V source is connected to a 6 Ω load?

30 Ω Signup and view all the answers

In the first example provided, what is the relationship between the power consumed by the load and the power in the source?

Equal Signup and view all the answers

At what circuit current does the source consume 6 W when connected to an 18 Ω load?

1.5 A Signup and view all the answers

In which region should Rload be less than Rsource to minimize heat generation in the source?

Region 3 Signup and view all the answers

What does connecting an 18 Ω load to a 24 V source result in terms of power in the load?

18 W Signup and view all the answers

If a 24 V source is connected to a 6 Ω load, what is the circuit current?

2 A Signup and view all the answers

What is the impedance transformation ratio when the impedance values of each side of the transformer are compared in a ratio?

16:1 Signup and view all the answers

In terms of transformer ratings, what determines the maximum current that can be carried by a transformer winding?

Insulation between the windings Signup and view all the answers

What is the relationship between the impedance transformation ratio and the turns ratio squared in a transformer?

Directly proportional Signup and view all the answers

Which factor determines the maximum voltage that can safely be applied to any winding in a transformer?

Insulation between the windings Signup and view all the answers

How does a higher maximum voltage on transformer windings relate to the type of insulation used between them?

Better (thicker) insulation allows a higher voltage Signup and view all the answers

What is the relationship between the voltage transformation ratio and the impedance transformation ratio in the transformer discussed?

Directly proportional Signup and view all the answers

What is the main purpose of impedance matching in a circuit?

To maximize the power transferred from the source to the load Signup and view all the answers

In the example provided, what is the power dissipated in the $6 \Omega$ load when connected to the $24 V$ source with $6 \Omega$ internal impedance?

$18 W$ Signup and view all the answers

What happens when the load impedance is not matched to the source impedance?

The power transfer is not maximized Signup and view all the answers

In the example provided, what is the power dissipated in the $6 \Omega$ source when connected to the $6 \Omega$ load?

$54 W$ Signup and view all the answers

What is the main reason why the source in the example is consuming three times the power of the load?

The load impedance is not matched to the source impedance Signup and view all the answers

What is the key concept demonstrated in the example of the $24 V$ source with $6 \Omega$ internal impedance connected to a $2 \Omega$ load?

The need for impedance matching to maximize power transfer Signup and view all the answers

What is the primary function of an auto-transformer as described in the text?

To provide a variable-output voltage Signup and view all the answers

What is the relationship between the voltage across the secondary winding and the voltage across the primary winding in an auto-transformer?

The secondary voltage has the same relationship to the primary voltage as if they were two distinct windings Signup and view all the answers

What does the movable tap in an adjustable auto-transformer allow the user to do?

Both increase and decrease the voltage relative to the primary voltage Signup and view all the answers

What is the relationship between the voltages available at the different tap points on an adjustable auto-transformer?

The voltage between points A and B can be either higher or lower than the voltage between points A and C, depending on the tap position Signup and view all the answers

What is the primary difference between a transformer and an auto-transformer as described in the text?

Auto-transformers have a single coil of wire that is tapped, rather than separate primary and secondary windings Signup and view all the answers

What is the main advantage of an auto-transformer over a regular transformer mentioned in the text?

Auto-transformers provide more flexibility in adjusting the output voltage Signup and view all the answers