Principles of Electronic Communication Systems 4th Edition
Frenzel Solutions Manual
What is Gain? and what's it's ration - ANSWER: Gain means amplification.
Output/Inside
How do you calculate the total gain of cascaded gains? - ANSWER: They are
multiplied by one another.
What is Attenuation? - ANSWER: Attenuation refers to a loss introduced by a circuit
or component.
How do you calculate the total gain of a cascaded circuit? - ANSWER: Each circuit
gain is multiplied by the next.
How do you calculate the attenuation factor of a cascaded circuit? - ANSWER: Each
circuit loss is multiplied by the next.
It is not common in communication systems and equipment to cascade circuits and
components that have gain and attenuation.
True or False - ANSWER: False
What are Decibels? - ANSWER: The gain or loss of a circuit is usually expressed in
decibels (dB),
____ was a unit of measurement that was originally created as a way of expressing
the hearing response of the human ear to various sound levels. - ANSWER: Decibel
What is 1/10 a decebel? - ANSWER: A bel
What is the formula for calculating Decibel gains or losses for Voltage and Current? -
ANSWER: 20 * log10 (Vo / Vin)
20 * log10 (Io / Iin)
What is the formula for calculating Decibel gains or losses for Power? - ANSWER: 10
* log10 (Po / Pin)
How do you calculate the overall decibel gain or attenuation of a circuit or system -
ANSWER: You simply add the decibel gain and attenuation factors of each circuit
Ratios less than 1 give negative decibel values
, True or False? - ANSWER: True
Does a 2:1 ratio represents a 3-dB power gain or a 6-dB voltage gain.
True or False - ANSWER: True
Why is expressing gain or attenuation in decibels not always a very good idea? -
ANSWER: When the ratio is computed, the units of voltage or power are canceled,
making the ratio a dimensionless, or relative, figure. When you see a decibel value,
you really do not know the actual voltage or power values.
The least perceptible sound (hearing threshold) - ANSWER: 0 dB
The Intensity of a Normal Conversation? - ANSWER: 65 dB
The pain threshold of sound. - ANSWER: 120 dB
What is dBm? - ANSWER: It is a reference value used to compare any other value
when calculating gain or attenuation. Usually When a decibel value is computed by
comparing a power value to 1 mW
How do you calculate dBm? - ANSWER: 10 * log10 (Po / 0.001) in Watts
What are Tuned Circuits made up of? - ANSWER: Circuits made up of inductors and
capacitors that resonate at specific frequencies.
What is Reactance? - ANSWER: Reactance is an opposition that directly affects the
amount of current in a circuit.
Reactive components do not produce a phase shift between the currents and
voltages in a circuit.
True or False - ANSWER: False
Capacitance causes the current to lead the applied voltage
True or False? - ANSWER: True
Inductance does not causes the current to lag the applied voltage.
True or False? - ANSWER: False
What are the functions of Capacitors in A.C. circuits? - ANSWER: A capacitor used in
an ac circuit continually charges and dis- charges. A capacitor tends to oppose
voltage changes across it.
Frenzel Solutions Manual
What is Gain? and what's it's ration - ANSWER: Gain means amplification.
Output/Inside
How do you calculate the total gain of cascaded gains? - ANSWER: They are
multiplied by one another.
What is Attenuation? - ANSWER: Attenuation refers to a loss introduced by a circuit
or component.
How do you calculate the total gain of a cascaded circuit? - ANSWER: Each circuit
gain is multiplied by the next.
How do you calculate the attenuation factor of a cascaded circuit? - ANSWER: Each
circuit loss is multiplied by the next.
It is not common in communication systems and equipment to cascade circuits and
components that have gain and attenuation.
True or False - ANSWER: False
What are Decibels? - ANSWER: The gain or loss of a circuit is usually expressed in
decibels (dB),
____ was a unit of measurement that was originally created as a way of expressing
the hearing response of the human ear to various sound levels. - ANSWER: Decibel
What is 1/10 a decebel? - ANSWER: A bel
What is the formula for calculating Decibel gains or losses for Voltage and Current? -
ANSWER: 20 * log10 (Vo / Vin)
20 * log10 (Io / Iin)
What is the formula for calculating Decibel gains or losses for Power? - ANSWER: 10
* log10 (Po / Pin)
How do you calculate the overall decibel gain or attenuation of a circuit or system -
ANSWER: You simply add the decibel gain and attenuation factors of each circuit
Ratios less than 1 give negative decibel values
, True or False? - ANSWER: True
Does a 2:1 ratio represents a 3-dB power gain or a 6-dB voltage gain.
True or False - ANSWER: True
Why is expressing gain or attenuation in decibels not always a very good idea? -
ANSWER: When the ratio is computed, the units of voltage or power are canceled,
making the ratio a dimensionless, or relative, figure. When you see a decibel value,
you really do not know the actual voltage or power values.
The least perceptible sound (hearing threshold) - ANSWER: 0 dB
The Intensity of a Normal Conversation? - ANSWER: 65 dB
The pain threshold of sound. - ANSWER: 120 dB
What is dBm? - ANSWER: It is a reference value used to compare any other value
when calculating gain or attenuation. Usually When a decibel value is computed by
comparing a power value to 1 mW
How do you calculate dBm? - ANSWER: 10 * log10 (Po / 0.001) in Watts
What are Tuned Circuits made up of? - ANSWER: Circuits made up of inductors and
capacitors that resonate at specific frequencies.
What is Reactance? - ANSWER: Reactance is an opposition that directly affects the
amount of current in a circuit.
Reactive components do not produce a phase shift between the currents and
voltages in a circuit.
True or False - ANSWER: False
Capacitance causes the current to lead the applied voltage
True or False? - ANSWER: True
Inductance does not causes the current to lag the applied voltage.
True or False? - ANSWER: False
What are the functions of Capacitors in A.C. circuits? - ANSWER: A capacitor used in
an ac circuit continually charges and dis- charges. A capacitor tends to oppose
voltage changes across it.
