Solutions to Homework 9
Electric Circuits: ELEC 221
Chapter 7
1
70. In the circuit in Fig. P70, switch A has been open and switch B has been closed for a long
time. At t = 0, switch A closes. Five seconds after switch A closes, switch B opens. Find iL(t)
Solutions to Homework 2
Electric Circuits: ELEC 221
1. If the interconnection in Fig. P1 is valid, find the total power developed in the
circuit. If the interconnection is not valid, explain why.
Figure P1
Solution:
The interconnect is valid since the vol
Solutions to Homework 3
Electric Circuits: ELEC 221
1
2. For each of the circuits shown in the following gures, a) identify the resistors connected in parallel, b)
simplify the circuit by replacing the parallel-connected resistors with equivalent resistor
ELEC 221 Circuit Theory
Chapter 7: First Order Response
By: Dr. Yan-Fei Liu
Email: [email protected]
Introduction
In chapter 6, we learnt how to derive the
voltage, current, power, and energy of
capacitors and inductors in very simple
circuits.
Mostl
ELEC 221 Circuit Theory
Chapter 8: Response of R, L, and C
Circuit
By: Dr. Yan-Fei Liu
Email: [email protected]
Chapter 8: Introduction
In this chapter we study circuits with both a
capacitor and in inductor: RLC circuits.
These are obviously 2nd or
ELEC 221 Circuit Theory
Chapter 8: Response of R, L, and C
Circuit
By: Dr. Yan-Fei Liu
Email: [email protected]
Chapter 8: Introduction
In this chapter we study circuits with both a
capacitor and in inductor: RLC circuits.
These are obviously 2nd or
ELEC 221 Circuit Theory
Chapter 6: Inductance, Capacitance
and Mutual Inductance
By: Dr. Yan-Fei Liu
Email: [email protected]
Chapter 6: Introduction
Last 2 ideal elements encountered in this course
are introduced: Capacitors (C) and Inductors
(L): p
ELEC 221 Circuit Theory
Chapter 9: Sinusoidal Steady-State Analysis
By: Dr. Yan-Fei Liu
Email: [email protected]
Chapter 9: Sinusoidal Steady-State Analysis
Thus far, we have studied:
Resistive circuits: any input or excitation1 is easy
to consider a
ELEC 221 Circuit Theory
Chapter 6: Inductance, Capacitance
and Mutual Inductance
By: Dr. Yan-Fei Liu
Email: [email protected]
Chapter 6: Introduction
Last 2 ideal elements encountered in this course
are introduced: Capacitors (C) and Inductors
(L): p
ELEC 221 Circuit Theory
Chapter 4: Circuit Analysis
By: Dr. Yan-Fei Liu
Email: [email protected]
Simplifying Circuits
In circuit analysis, it might be beneficiary to
simplify parts of the circuit we deal with.
We can replace a sub-circuit/circuit by
ELEC 221 Circuit Theory
Chapter 4: Circuit Analysis
By: Dr. Yan-Fei Liu
Email: [email protected]
Simplifying Circuits
In circuit analysis, it might be beneficiary to
simplify parts of the circuit we deal with.
We can replace a sub-circuit/circuit by
ELEC 221 Circuit Theory
Chapter 9: Sinusoidal Steady-State Analysis
By: Dr. Yan-Fei Liu
Email: [email protected]
Chapter 9: Sinusoidal Steady-State Analysis
Thus far, we have studied:
Resistive circuits: any input or excitation1 is easy
to consider a
ELEC 221 Circuit Theory
Chapter 4: Circuit Analysis
By: Dr. Yan-Fei Liu
Email: [email protected]
Techniques of Circuit Analysis
Analyzing or solving a circuit: finding all the
voltages and currents (of all the branches).
Direct method: we write a co
ELEC 221 Circuit Theory
Chapter 7: First Order Response
By: Dr. Yan-Fei Liu
Email: [email protected]
Introduction
In chapter 6, we learnt how to derive the
voltage, current, power, and energy of
capacitors and inductors in very simple
circuits.
Mostl
ELEC 221: Circuit Theory
Chapter 1: Circuit Variables
Dr. Yan-Fei Liu
[email protected]
1
Voltage
Definition: Voltage is the energy required
per unit of charge for separation.
Voltage (Volt, V)
dw
v=
dq
Energy (Joule, J)
Charge (Coulomb, C)
16
Curren
Elec 221: Electric Circuits
Solution to Homework 8
7.3 The switch in the circuit in Fig. P7.3 has been open for a long time. At t = 0 the
switch is closed.
a) Determine io (0+) and io ().
b) Determine io (t) for t 0+.
c) How many milliseconds after the sw
Solution to Homework 11
Electric Circuits: ELEC 221
9.1 Consider the sinusoidal voltage
v(t) = 80 cos (1000t - 30) V.
a) What is the maximum amplitude of the voltage?
b) What is the frequency in hertz?
c) What is the frequency in radians per second?
d) Wh
Solutions to Homework 12
Electric Circuits: ELEC 221
9.61 Use the mesh-current method to find the steady-state expression for io(t) in the circuit in Fig. P9.61 if
Solution:
9.64 Use the mesh-current method to find the steady-state expression for vo in th
Quiz 7
Problem 7.32
At the time the switch is closed in the circuit shown in Fig. P7.32, the capacitors are charged as shown.
a) Find vo(t) for t 0+.
b) What percentage of the total energy initially stored in the three capacitors is dissipated in the 250
Quiz 8
Problem 8.32
The switch in the circuit in Fig. P8.32 has been open a long time before closing at t = 0. Find iL(t) for t 0
Solution:
Problem 8.44
In the circuit in Fig. P8.44, the resistor is adjusted for critical damping. The initial capacitor vol
Pl/I
some 1m ml Exam,£t_ec.22r, an 2°13, s. Venn-
Page 2 of 19
[10 marks] The xedattenuator pad shown in the following gure is called
a bridged tee. Show/ prove that:
(i) If R = RL, then Rab 3 RL.
(ii) If R = RL,t.11en =
' 01 61E?» 4V) l/V(o): JECQQZJ
Solutions to Homework 5
Electric Circuits: ELEC 221
1
4.4) Assume the current ig in the circuit in Fig. P4 is known. The resistors R1 - R5 are also
known.
a) How many unknown currents are there?
b) How many independent equations can be written using Kirch
Solutions to Homework 7
Electric Circuits: ELEC 221
6.5 The current in and the voltage across a 5 H inductor are known to be zero for t0. The
voltage across the inductor is given by the graph in figure below for t 0.
a) Derive the expression for the curre
Solutions to Homework 1
Electric Circuits: ELEC 221
1
9. A current of 1600 A exists in a rectangular (0.4-by-16 cm) bus bar. The current is due to free
electrons moving through the wire at an average velocity of v meters/second. If the concentration of
fr
Solutions to Homework 6
Electric Circuits: ELEC 221
62. a) Use source transformations to find o in the circuit in Fig. P62.
b) Find the power developed by the 520 V source.
c) Find the power developed by the 1 A current source.
d) Verify that the total po
Solution to Homework 4
Elec 221: Electric Circuits
1
3.31 A d'Arsonval voltmeter is shown in Fig. P3.31. Find the value of Rv for each of the
following full-scale readings: (a) 50 V, (b) 5v, (c) 250mV and (d) 25mV.
Solution:
For all full-scale readings th
ELEC 221 Circuit Theory
Chapter 10: Sinusoidal Steady-State:
Power Calculations
By: Dr. Yan-Fei Liu
Email: [email protected]
10.1 Instantaneous Power
Power and energy in SSS are very important:
Generation and Delivery of power is all sinusoidal.
Powe