How Does the Transfer Function Affect Sinusoidal Inputs?

AI Thread Summary
The discussion revolves around the effect of a transfer function on sinusoidal inputs, specifically G(s) = 4/(s+1) and the input 2 sin(10t + 10). The magnitude of the transfer function is calculated as 4/sqrt(101) with a phase angle of -84 degrees. Clarification is provided that the amplitude of the output should be the product of the transfer function's gain and the input's amplitude, not a sum. Additionally, it is noted that the frequency in the input is in radians, making it incorrect to directly add phase angles. Understanding these principles is crucial for accurately determining the output response.
noobish
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Homework Statement



This is related to the frequency response topic.
Given transfer function G(s) = 4/(s+1)
and input is sinusoidal i.e. 2 sin (10t + 10)

Homework Equations



None.

The Attempt at a Solution



I have found out that the magnitude of the transfer function G(s) is 4/sqrt(101) with phase angle -84 degree.

Is the output
(4/sqrt(101) + 2) sin (10t - 74) ?
because that is what i was told.

All these while I thought that the magnitude of G(s) have to be multiplied with the magnitude of the input sinusoidal to obtain the magnitude of the output. But in this case, he just add both of them together.
Please clarify. =)
 
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noobish said:

Homework Statement



This is related to the frequency response topic.
Given transfer function G(s) = 4/(s+1)
and input is sinusoidal i.e. 2 sin (10t + 10)

Homework Equations



None.

The Attempt at a Solution



I have found out that the magnitude of the transfer function G(s) is 4/sqrt(101) with phase angle -84 degree.

Is the output
(4/sqrt(101) + 2) sin (10t - 74) ?
because that is what i was told.

All these while I thought that the magnitude of G(s) have to be multiplied with the magnitude of the input sinusoidal to obtain the magnitude of the output. But in this case, he just add both of them together.
Please clarify. =)

First of all the 10 in sin(10t + 10) is radians, so you can not add it to -84 degree and obtain 74 radians.
And yes, the gain of the transfer function must be multiplied by and not summed to the amplitude.
 
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