Question

SULIT (EKT 318) (d) An electrical circuit is shown in Figure 1.2. Litar elektrik ditunjukkan seperti dalam Rajah 1.2) i) Determine transfer function G(s)-I(s)/E(s) of the electrical system. Tentukan fungsi rangkap pindah G (s) I(s)/E(s) sistem elektrik ini.) 6 Marks Markah] ii) Evaluate the effect of a step input on the output of the system. Nilaikan kesan masukan unit langkah kepada keluaran sistem ini. 2 Marks /Markah (Assume, L = 50H, R= 10 Ohm, C = 0.001 Farad and 0 initial conditions.) (Anggapkan, L -50H, R 10 Ohm, C-0.001 Farad and 0 syarat mula.) e(t) 0 Figure 1.2 Rajah 1.2

Answer 1

L = 50 h R = 10 ohm c = 0.001 f E (s) = I (s) times (R + LS + 1/cs) doublerightarrow I (s)/E (s) = 1/R + LS + 1/cs = CS/RCS + LCS^2 + 1 Divide N^2 and D^2 by LC doublerightarrow I (s)/E (s) = CS/LC/RCS + LCS^2 + 1/LC = 1/L S/R/L S + S^2 + 1/LC doublerightarrow G (s) = I (s)/E (s) = (1/L) S/s^2 + R/L S + 1/LC Put R, L, C value, we get G (s) = I (s)/E (s) = (1/50) S/s^2 + 10/50 s + 1/50 times 0.001 = (1/50) s/s^2 + s/5 + 20 or G (s) = I (S)/E (S) = 0.025/s^2 + 0.25 + 20 output when E (s) = 1/s I (s) = 0.02/s^2 + 0.2 s + 20 o/p = I (s) times 1/CS = 0.2/0.0015 (s^2 + 0.25 + 20) doublerightarrow o/p = 20/s (s^2 + 0.25 + 20)