MAE 2381 QUIZ 3 (CH. 6, 7)EXAM
QUESTIONS WITH COMPLETE
SOLUTIONS 2025
Definition of Gain - ANSWERa signal with lower amplitude amplified to a higher
amplitude, the amplification factor is the gain
Gain Equation - ANSWERG = Aa/A0
G is the gain
Aa is the amplified amplitude
A0 is the original amplitude
Magnitude Ratio Definition - ANSWERwhen a signal's amplitude is modified by some
process, such as filtering OR a system response
the degree of modification is the magnitude ratio
Magnitude Ratio Equation - ANSWERM(w) = Mm/M0
where M(omega) is the magnitude ratio
Mm is the modified magnitude
M0 is the original magnitude
Linear vs. Log Presentations of Gain and Magnitude Ratio - ANSWER-linear forms
of gain and magnitude ratio are more suited for relatively small changes in
amplitude/magnitude
-when phenomena have a large dynamic range (larger changes in
amplitude/magnitude), log scales are more important
-log scales expressed in the Decibel format
Decibel Expressions - ANSWERThere are two main decibel expressions:
1. For voltage or similar quantity
Gain = 10log(Modified Amplitude/Reference)
2. For power or similar quantity
Gain = 20log(Modified Amplitude/Reference)
Decibel Equation - ANSWERdB = 10log(I/Io)
where we are using log base 10
I = intensity
QUESTIONS WITH COMPLETE
SOLUTIONS 2025
Definition of Gain - ANSWERa signal with lower amplitude amplified to a higher
amplitude, the amplification factor is the gain
Gain Equation - ANSWERG = Aa/A0
G is the gain
Aa is the amplified amplitude
A0 is the original amplitude
Magnitude Ratio Definition - ANSWERwhen a signal's amplitude is modified by some
process, such as filtering OR a system response
the degree of modification is the magnitude ratio
Magnitude Ratio Equation - ANSWERM(w) = Mm/M0
where M(omega) is the magnitude ratio
Mm is the modified magnitude
M0 is the original magnitude
Linear vs. Log Presentations of Gain and Magnitude Ratio - ANSWER-linear forms
of gain and magnitude ratio are more suited for relatively small changes in
amplitude/magnitude
-when phenomena have a large dynamic range (larger changes in
amplitude/magnitude), log scales are more important
-log scales expressed in the Decibel format
Decibel Expressions - ANSWERThere are two main decibel expressions:
1. For voltage or similar quantity
Gain = 10log(Modified Amplitude/Reference)
2. For power or similar quantity
Gain = 20log(Modified Amplitude/Reference)
Decibel Equation - ANSWERdB = 10log(I/Io)
where we are using log base 10
I = intensity
