David J. Griffiths, Reed College
ISBN #9780138053260
3rd Edition
533 Questions
Homework Questions
Introduction to Electrodynamics is a comprehensive exploration of the principles that govern electric and magnetic fields, seamlessly bridging mathematical foundations with real-world applications. The book begins by establishing key vector analysis techniques and the basics of electrostatics, which set the stage for deeper dives into electric fields in matter and magnetostatics. It introduces special techniques and conservation laws, providing readers with advanced problem-solving strategies that pave the way for understanding electromagnetic waves and potentials. Throughout, the text interweaves theoretical concepts with practical insights, mirroring a narrative that evolves from foundational mathematics to the dynamic challenges of modern electrodynamics.
Chapter 1
Vector Analysis
Chapter 2
Electrostatics
Chapter 3
Special Techniques
Chapter 4
Electric Fields in Matter
Chapter 5
Magnetostatics
Chapter 6
Magnetic Fields in Matter
Chapter 7
Electrodynamics
Chapter 8
Conservation Laws
Chapter 9
Electromagnetic Waves
Chapter 10
Potentials and Fields
Chapter 11
Radiation
Chapter 12
Electrodynamics and Relativity
Problem 1
Using the definitions in Eqs. 1.1 and $1.4,$ and appropriate diagrams, show that the dot product and cross product are distributive, a) when the three vectors are coplanar; b) in the general case.
Amit Srivastava Numerade Educator
Problem 2
(a) Twelve equal charges, $q,$ are situated at the corners of a regular 12 -sided polygon (for instance, one on each numeral of a clock face). What is the net force on a test charge $Q$ at the center? (b) Suppose one of the $12 q$ 's is removed (the one at " 6 o'clock"). What is the force on $Q ?$ Explain your reasoning carefully. (c) Now 13 equal charges, $q$, are placed at the corners of a regular 13 -sided polygon. What is the force on a test charge $Q$ at the center? (d) If one of the $13 q$ 's is removed, what is the force on $Q ?$ Explain your reasoning.
Eduard Sanchez Numerade Educator
Problem 3
(a) Find the electric field (magnitude and direction) a distance $z$ above the midpoint between two equal charges, $q,$ a distance $d$ apart (Fig. 2.4 ). Check that your result is consistent with what you'd expect when $z \gg d$. (b) Repeat part (a), only this time make the right-hand charge $-q$ instead of $+q$.
David Morabito Numerade Educator
Problem 4
Find the electric field a distance $z$ above the center of a square loop (side $a$ ) carrying uniform line charge $\lambda$ (Fig. 2.8 ). [Hint: Use the result of Ex. 2.1.]
Problem 5
Calculate the force of magnetic attraction between the northern and southern hemispheres of a uniformly charged spinning spherical shell, with radius $R$, angular velocity $\omega,$ and surface charge density $\sigma .[\text { This is the same as Prob. } 5.42,$ but this time use the Maxwell stress tensor and Eq. $8.22 .$
Manik Pulyani Numerade Educator
Problem 6
Two concentric metal spherical shells, of radius $a$ and $b$, respectively, are separated by weakly conducting material of conductivity $\sigma$ (Fig. 7.4 a). (a) If they are maintained at a potential difference $V$, what current flows from one to the other: (b) What is the resistance between the shells? (c) Notice that if $b \gg a$ the outer radius ( $b$ ) is irrelevant. How do you account for that? Exploit this observation to determine the current flowing between two metal spheres, each of radius $a,$ immersed deep in the sea and held quite far apart (Fig. $7.4 b$ ), if the potential difference between them is $V$. (This arrangement can be used to measure the conductivity of sea water.
Thomas Tamanaha Numerade Educator
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