question 1 60 marks a the combination of resistors capacitors c1 c2 c3

Question

Question 1 (60 marks)
(a) The combination of resistors capacitors C1, C2, C3 and C4 in Fig. 1(a) is
equivalent to a single capacitor Ceq.
Calculate the value of Ceq when C1 = (1000 + a) nF, C2 = (2000+ B) nF, C3 =
(3000 + y) nF and C4 = (4000 + ō) nF.
C1
Ceq
C2
C4
C3
Figure 1(a)
Ceq
15%/n(b) Referring to Fig. 1(b), calculate the dc steady state voltage VL across the load
resistor RL.
Rs = (50 + 5) Q, C1 = (2000 + ε) nF, L2 = (300 + a) µH, C3 = (4000+ 0) nF, and
RL = (50 + A) Q. Vs= 3 V.
Rs
Vs
VL (in dc steady state)
SPICE circuit schematic
C1
L2
Figure 1(b)
C3
RL
+
VL
15%
5%/n(c) Calculate the magnitudes and phases of the phasor representations of the
following quantities:
(1)
(ii)
(III)
(iv)
(i)
(ii)
where f = (1000 + 3) kHz, Is = (100 + a) μA, Vs (2500 + 5) mV, R = (1800 + ε)
Q2, L= (2200 +λ) µH, C = (470+ n) pF,
(iv)
i₁ (t) = 1, cos(wt + 0.5)
v₂ (t) = V.sin(wt - 1.2)
2
Z3 (w) = R + jwL
R
Magnitude (with units)
Z4 (w) =
1 + jwCR
Phase (degrees)
Phase (radians)
30%/n(d) At time t = 0, the capacitor C in Fig. 1(d) is charged to Vc = +1V and the switch S
is open. The switch is closed at time t = 100 µs, connecting the voltage source
Vs to the RC network. Calculate the voltage on the capacitor at time t = 200 µs.
ⒸUCD 2023/2024
Page 5 of 8
Vs = (3000 + a) mV, R = (2200 + B) Q, and C = (100 + y) nF.
S
Vc(200µs)
Vs
R
www
+
C = Vc
Figure 1 (d)
20%