3.3 Capacitance & Field Energy

Irodov Problems 3.101 to 3.146.

46problems
81figures
Difficulty2.3avgDifficulty: 3 rated 1, 30 rated 2, 11 rated 3, 2 rated 4, 0 rated 5; mean 2.3.
Uniqueness2.8avgUniqueness: 0 rated 1, 16 rated 2, 22 rated 3, 7 rated 4, 1 rated 5; mean 2.8.

No.	Title	Difficulty	Uniqueness	Methods
3.101	A Coat That Raises Capacitance	Difficulty 2 of 5	Uniqueness 2 of 5	gauss law · dielectric polarization · electric potential · capacitance
3.102	Filling One Capacitor Weakens Its Field	Difficulty 2 of 5	Uniqueness 3 of 5	capacitor networks · capacitance · dielectric polarization
3.103	Two Layers Share One Displacement	Difficulty 2 of 5	Uniqueness 2 of 5	dielectric boundary · gauss law · capacitance · dielectric polarization
3.104	Lines That End Inside the Filling	Difficulty 3 of 5	Uniqueness 3 of 5	dielectric polarization · gauss law · capacitance
3.105	A Dielectric That Flattens the Field	Difficulty 2 of 5	Uniqueness 3 of 5	gauss law · capacitance · dielectric polarization
3.106	Two Weak Spots Failing Together	Difficulty 2 of 5	Uniqueness 3 of 5	gauss law · dielectric boundary · capacitance
3.107	The Inner Layer Sets the Limit	Difficulty 2 of 5	Uniqueness 2 of 5	gauss law · electric potential · dielectric boundary · capacitance
3.108	Two Wires, One Logarithm	Difficulty 2 of 5	Uniqueness 2 of 5	superposition · gauss law · electric potential · capacitance
3.109	A Wire Facing Its Own Image	Difficulty 2 of 5	Uniqueness 3 of 5	method of images · electric potential · capacitance
3.110	Two Distant Balls in Series	Difficulty 2 of 5	Uniqueness 2 of 5	electric potential · superposition · capacitance · approximation expansion
3.111	A Ball Barely Notices the Plane	Difficulty 2 of 5	Uniqueness 2 of 5	method of images · electric potential · capacitance · approximation expansion
3.112	Wires That Fold a Chain Flat	Difficulty 2 of 5	Uniqueness 3 of 5	capacitor networks · symmetry · electric potential
3.113	The Wiring Decides Which Gaps Pair	Difficulty 2 of 5	Uniqueness 3 of 5	capacitance · capacitor networks · conductor equilibrium
3.114	The Smaller Capacitor Breaks First	Difficulty 2 of 5	Uniqueness 2 of 5	capacitor networks · capacitance · optimization
3.115	Two Dividers Stacked in a Row	Difficulty 3 of 5	Uniqueness 3 of 5	capacitor networks · conductor equilibrium · electric potential
3.116	The Ladder That Contains Itself	Difficulty 3 of 5	Uniqueness 4 of 5	capacitor networks · symmetry · limiting cases
3.117	The Source Adds to the Drop	Difficulty 2 of 5	Uniqueness 2 of 5	capacitor networks · kirchhoff rules · conductor equilibrium
3.118	Two Sources Pulling Against Each Other	Difficulty 2 of 5	Uniqueness 2 of 5	capacitor networks · kirchhoff rules · conductor equilibrium
3.119	One Charge for Both Capacitors	Difficulty 2 of 5	Uniqueness 2 of 5	capacitor networks · kirchhoff rules · conductor equilibrium
3.120	A Bridge Balanced by Capacitance Ratios	Difficulty 3 of 5	Uniqueness 3 of 5	capacitor networks · conductor equilibrium · electric potential
3.121	Sharing Charge with a Series Pair	Difficulty 2 of 5	Uniqueness 2 of 5	capacitor networks · conductor equilibrium · field energy
3.122	Closing the Switch Empties One Capacitor	Difficulty 3 of 5	Uniqueness 3 of 5	capacitor networks · kirchhoff rules · capacitance
3.123	The Middle Wire Splits the Series Pair	Difficulty 2 of 5	Uniqueness 2 of 5	capacitor networks · capacitance · kirchhoff rules
3.124	Three Plates Sharing One Island	Difficulty 2 of 5	Uniqueness 3 of 5	capacitor networks · electric potential · capacitance
3.125	The Floating Wire Keeps Zero Charge	Difficulty 3 of 5	Uniqueness 3 of 5	capacitor networks · electric potential · symmetry
3.126	Crossing the Arms Wakes the Rung	Difficulty 3 of 5	Uniqueness 3 of 5	capacitor networks · symmetry · capacitance
3.127	Six Pairs on a Square	Difficulty 1 of 5	Uniqueness 2 of 5	coulomb law · superposition · electric potential
3.128	A Logarithm in a Charge Chain	Difficulty 2 of 5	Uniqueness 4 of 5	superposition · electric potential · approximation expansion
3.129	The Image Sets the Energy	Difficulty 2 of 5	Uniqueness 3 of 5	method of images · electric potential · field energy
3.130	Charged Balls Interact Like Points	Difficulty 3 of 5	Uniqueness 3 of 5	gauss law · symmetry · electric potential
3.131	Charge Survives, a Third Is Kept	Difficulty 2 of 5	Uniqueness 4 of 5	field energy · capacitor networks · joule heating · rc transient
3.132	A Mirror Move That Still Heats	Difficulty 4 of 5	Uniqueness 4 of 5	capacitor networks · work energy · joule heating · symmetry
3.133	The Heat Ignores the Working Cell	Difficulty 3 of 5	Uniqueness 4 of 5	capacitor networks · work energy · joule heating
3.134	Two Shells, Three Energies	Difficulty 2 of 5	Uniqueness 3 of 5	field energy · gauss law · superposition
3.135	One Sixth of the Energy Inside	Difficulty 2 of 5	Uniqueness 3 of 5	field energy · gauss law
3.136	Energy Stored in a Dielectric Shell	Difficulty 1 of 5	Uniqueness 2 of 5	field energy · gauss law · dielectric polarization
3.137	The Field Pays for Expansion	Difficulty 1 of 5	Uniqueness 2 of 5	field energy · work energy · gauss law
3.138	Expanding Shell Spends Two Energies	Difficulty 2 of 5	Uniqueness 3 of 5	field energy · energy conservation · electric potential
3.139	Pressure from a Shell's Energy	Difficulty 2 of 5	Uniqueness 3 of 5	field energy · work energy · electrostatic force
3.140	Pulling a Charge Out of Its Cage	Difficulty 3 of 5	Uniqueness 4 of 5	field energy · conductor equilibrium · gauss law · work energy
3.141	Fixed Charge Versus Fixed Voltage	Difficulty 2 of 5	Uniqueness 3 of 5	capacitance · field energy · work energy · electrostatic force
3.142	Work to Pull Out a Slab	Difficulty 2 of 5	Uniqueness 2 of 5	capacitance · field energy · dielectric boundary · limiting cases
3.143	The Field Squeezes the Water	Difficulty 4 of 5	Uniqueness 5 of 5	electrostatic force · field energy · dielectric boundary · hydrostatics
3.144	A Charged Capacitor Lifts the Liquid	Difficulty 3 of 5	Uniqueness 4 of 5	field energy · dielectric boundary · hydrostatics · electrostatic force
3.145	The Pull That Ignores Depth	Difficulty 2 of 5	Uniqueness 3 of 5	capacitance · field energy · electrostatic force · work energy
3.146	A Constant Torque on a Turned Plate	Difficulty 2 of 5	Uniqueness 3 of 5	capacitance · field energy · electrostatic force · torque