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If the unit step response of a network is (1 – e–αt), then its unit impulse response will be—
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- α e– αt
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1 e–t/α α -
1 αe–t/α - (1 – α) e– αt
Correct Option: A
In order to calculate the unit impulse response first we will obtain transfer function i.e. H (S)
given y (t) = 1 – e– α t
Y (s) = | - | = | s | s2 (s + α) | s(s + α) |
we know that
H (s) = | X (s) |
X (t) = u (t)
X (s) = | s |
so, H (s) = | = | S(s + α) 1 / S | s + α |
Now, according to the question
x (t) = δ (t)
so, X (s)=1
Y (t)=?
Now, Y (s) = H (S) X (S)
or Y (S) = | . 1 | s + α |
or Y (S) = | s + α |
or Y (t) = α. e– αt