Engineering Circuit Analysis, 10th Edition
Author: William H. Hayt
Edition: 10th Edition
,Chapter 1: Error Analysis and Approximations
1. Solving the transcendental equation graphically
Equation:
[
\frac{3 \theta - \sin \theta}{\theta^3} = 0.01
]
Graphical or iterative solution shows the linear approximation is valid up to θ ≈ 0.245
radians for 1% accuracy.
This is the limit of the small-angle linear approximation.
2. Relative error for function:
[
f(x) = \frac{1}{1+x}
]
Relative error formula:
[
\text{Rel Error} = \frac{|(1/(1+x) - 1)|}{1} = |x| \quad \Rightarrow \quad x = \pm 0.1
]
So the approximation holds for x = ±0.1.
3. RC Circuit voltage error analysis
Voltage across capacitor:
[
V_C = V_0(1 - e^{-t/\tau})
]
Relative error:
[
\text{Rel Error} = \frac{(V_0 - V_C) + (C_0 - C)}{\text{...}} \approx 5.1% \text{ for ΔC/C =
0.1, } 28% \text{ for ΔC/C = 0.5}
]
Time constant cancels out in the relative error expression.
,Chapter 2: Engineering Notation, SI Units, and Power Calculations
1. Convert to engineering notation:
Given Engineering Notation
0.045 W 45 mW
2000 pJ 2 nJ
0.1 ns 100 ps
39,212 as 39.212 fs
18,000 m 18 km
2,500,000,000,000 bits 2.5 Tb
“zeta atom” unclear skip
2. More conversions:
Given Engineering Notation
1230 fs 1.23 ps
0.0001 dm 10 μm
1400 mK 1.4 K
32 nm 32 × 10⁻⁹ m
13,560 kHz 13.56 MHz
2021 μmol 2.021 mmol
13 dl 1.3 L
1 hm 100 m
3. Express in engineering units:
Given Engineering Notation
1212 mV 1.212 V
10¹² pA 100 mA
1000 yoctoseconds 1 zs
13,100 as 13.1 fs
7.6 × 10²¹ zs 10 Ms
5.6 × 10⁻⁶ s 5 μs
10⁹ s 1 Gs
4. Distances in meters:
Prefix Meters
1 Zm 10²¹ m
, Prefix Meters
1 Em 10¹⁸ m
1 Pm 10¹⁵ m
1 Tm 10¹² m
1 Gm 10⁹ m
1 Mm 10⁶ m
5. Temperatures to SI:
(212°F = 373.15 K)
(0°F = 255.37 K)
0K=0K
200 hp = 149.14 kW
1 yard = 0.9144 m
1 mile = 1.6093 km
6. More SI conversions:
373.15 K, 273.15 K, 4.2 K
150 hp = 111.855 kW
500 Btu = 527.5 kJ
100 J/s = 100 W
7. Galactic years for 2 hours:
[
2 \text{ hours} = 9.13 \times 10^{-15} \text{ galactic years}
]
8. Krypton fluoride laser:
Pulse power: ( P = \frac{E}{t} = 36.667 \text{ MW} )
Max average power for 100 pulses/sec: ( 55 W )
9. Human daily food intake:
[
2500 \text{ kcal/day} = 121.15 W \text{ average power output}
]
10. Electric vehicle motor energy consumption:
Motor: 40 hp, run 3 h
Electrical energy consumed: (3.2214 \times 10^8 \text{ J} = 322.14 \text{ MJ})