Category: Part 3: Electricity

  • Problem 3.8 — Field of two parallel infinite planes

    Problem Statement Two infinite planes carry $+\sigma$ and $-\sigma$. Find the field in each of the three regions. Given Information All quantities, constants, and constraints stated in the problem above Physical constants used as needed (see Concepts section) Physical Concepts & Formulas This problem draws on fundamental physical principles. The key is to identify which…

  • Problem 3.5 — Field inside and outside a charged sphere

    Problem Statement A sphere of radius $R$ carries surface charge $q$. Find the field inside and outside. Given Information All quantities, constants, and constraints stated in the problem above Physical constants used as needed (see Concepts section) Physical Concepts & Formulas This problem draws on fundamental physical principles. The key is to identify which conservation…

  • Problem 3.6 — Field of a uniformly charged solid sphere

    Problem Statement A solid sphere of radius $R$ has volume charge density $\rho$. Find $E$ inside and outside. Given Information All quantities, constants, and constraints stated in the problem above Physical constants used as needed (see Concepts section) Physical Concepts & Formulas This problem draws on fundamental physical principles. The key is to identify which…

  • Problem 3.3 — Electric field of a uniformly charged disk

    Problem Statement Determine the electric field for the configuration described: A disk of radius $R$ has surface charge density $\sigma$. Find the field on the axis at distance $x$. Integrate ring contributions from $r=0$ to $R$: $$\boxed{E = \frac{\sigma}{2\varepsilon_0}\left(1-\frac{x}{\sqrt{R^2+x^2}}\right)}$$ Limits: infinite plane ($R\to\infty$): $E=\sigma/(2\varepsilon_0) Given Information Geometry and charge distribution as given in the problem…

  • Problem 3.4 — Field on axis of a uniformly charged line segment

    Problem Statement A wire of length $l$, linear charge density $\lambda$, is perpendicular to the point $P$ at distance $R$ from the midpoint. Given Information All quantities, constants, and constraints stated in the problem above Physical constants used as needed (see Concepts section) Physical Concepts & Formulas This problem draws on fundamental physical principles. The…

  • Problem 3.1 — Electric force between two charges

    Problem Statement Solve the Newton’s Laws / mechanics problem: Two charges $q_1 = +1.0\,\mu\text{C}$ and $q_2 = -2.0\,\mu\text{C}$ are placed $30\,\text{cm}$ apart. Find the force of interaction and the point on the line where the field is zero. By Coulomb’s law: $F = k|q_1||q_2|/r^2 = 8.99\times10^9\times2\times10^{-12}/0.09$ $$\boxed{F \approx 0.20\,\text{N ( Given Information Mass(es), forces, angles,…

  • Problem 3.2 — Electric field on axis of a charged ring

    Problem Statement Determine the electric field for the configuration described: A thin wire ring of radius $R$ carries charge $q$. Find the electric field on the axis at distance $x$. By symmetry transverse components cancel. Axial field: $$\boxed{E = \frac{qx}{4\pi\varepsilon_0(R^2+x^2)^{3/2}}}$$ Maximum at $x = R/\sqrt{2}$: $E_{\max} = \frac{q}{6\sqrt{3}\pi\varepsilon_0 R^2}$ Given Information Geometry and charge distribution…

  • Irodov Problem 3.374 — Electric Oscillations and AC Circuits

    Problem Statement Analyze the circuit: Irodov Problem 3.374 (Section 3.4: Electric Current): This problem concerns electric oscillations and ac circuits. Electric current involves the ordered motion of charge carriers driven by an electric field. The macroscopic laws (Ohm’s law, Kirchhoff’s laws, Joule heating) connect the microscopic ca Given Information Resistance values $R_1, R_2, \ldots$ as…

  • Irodov Problem 3.373 — Electric Oscillations and AC Circuits

    Problem Statement Analyze the circuit: Irodov Problem 3.373 (Section 3.4: Electric Current): This problem concerns electric oscillations and ac circuits. Electric current involves the ordered motion of charge carriers driven by an electric field. The macroscopic laws (Ohm’s law, Kirchhoff’s laws, Joule heating) connect the microscopic ca Given Information Resistance values $R_1, R_2, \ldots$ as…

  • Irodov Problem 3.372 — Electric Oscillations and AC Circuits

    Problem Statement Analyze the circuit: Irodov Problem 3.372 (Section 3.4: Electric Current): This problem concerns electric oscillations and ac circuits. Electric current involves the ordered motion of charge carriers driven by an electric field. The macroscopic laws (Ohm’s law, Kirchhoff’s laws, Joule heating) connect the microscopic ca Given Information Resistance values $R_1, R_2, \ldots$ as…