Category: Part 3: Electricity
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Problem 3.41 — Electric field inside a dielectric sphere
Problem Statement Determine the electric field for the configuration described: Irodov Problem 3.41. Uniform internal field in applied field $E_0$: $$\boxed{E_{\text{in}} = \frac{3E_0}{\varepsilon_r+2}}$$ Given Information Geometry and charge distribution as given in the problem Permittivity of free space $\varepsilon_0 = 8.85\times10^{-12}\,\text{C}^2\text{N}^{-1}\text{m}^{-2}$ Coulomb constant $k = 1/(4\pi\varepsilon_0) = 9\times10^9\,\text{N m}^2\text{C}^{-2}$ Physical Concepts & Formulas The electric…
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Problem 3.73 — EMF and non-electrostatic forces
Problem Statement Analyze the circuit: Irodov Problem 3.73. $\mathcal{E} = \oint(\mathbf{F}_{ne}/q)\cdot d\mathbf{l}$. Non-electrostatic forces (chemical, thermal) maintain potential difference against current flow. Given Information Resistance values $R_1, R_2, \ldots$ as specified EMF $\mathcal{E}$ and internal resistance $r$ of battery Any additional circuit elements given Physical Concepts & Formulas Ohm’s Law $V = IR$ and Kirchhoff’s…
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Problem 3.118 — Hall effect: carrier type
Problem Statement Solve the magnetic field/force problem: Irodov Problem 3.118. Direction of Hall voltage determines carrier sign. Positive Hall voltage $\Rightarrow$ holes (p-type); negative $\Rightarrow$ electrons (n-type). Given Information Current $I$ or charge $q$ and velocity $v$ as given Geometry (straight wire, loop, solenoid) as specified Permeability of free space $\mu_0 = 4\pi\times10^{-7}\,\text{T m A}^{-1}$…
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Problem 3.157 — Magnetostatics and magnetic forces
Problem Statement Solve the magnetic field/force problem: Irodov Problem 3.157 — Magnetostatics and magnetic forces. Key law: $B_{\text{wire}} = \mu_0 I/(2\pi r)$, torque $\tau = mB\sin\theta$, force $F = qvB\sin\theta$ This problem from the Magnetostatics and magnetic forces section requires applying the governing equation with the given geometry and nume Given Information Current $I$ or…
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Problem 3.253 — Electromagnetic induction
Problem Statement Solve the magnetic field/force problem: Irodov Problem 3.253 — Electromagnetic induction. This problem belongs to the section on Electromagnetic induction . Key principles: Faraday: $\mathcal{E} = -d\Phi/dt$; Lenz; motional EMF; inductance The solution proceeds by identifying the relevant physical configuration, applying the governing law Given Information Current $I$ or charge $q$ and velocity…
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Problem 3.42 — Polarization and bound charges
Problem Statement Irodov Problem 3.42. 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 law or field equation governs the system, then apply it systematically. Dimensional…
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Problem 3.74 — Drift velocity in copper
Problem Statement Solve the kinematics problem: Irodov Problem 3.74. $v_d = I/(neA) = 5/(8.5\times10^{28}\times1.6\times10^{-19}\times10^{-6}) = \boxed{3.68\times10^{-4}\,\text{m/s} \approx 0.37\,\text{mm/s}}$. Given Information Initial velocity $u$ (or $v_0$) Acceleration $a$ (constant unless stated otherwise) Time $t$ or distance $s$ as given Physical Concepts & Formulas Kinematics describes motion without reference to its cause. For constant acceleration, the four…
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Problem 3.119 — Field at centre of circular arc
Problem Statement Irodov Problem 3.119. 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 law or field equation governs the system, then apply it systematically. Dimensional…
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Problem 3.254 — Electromagnetic induction
Problem Statement Solve the magnetic field/force problem: Irodov Problem 3.254 — Electromagnetic induction. This problem belongs to the section on Electromagnetic induction . Key principles: Faraday: $\mathcal{E} = -d\Phi/dt$; Lenz; motional EMF; inductance The solution proceeds by identifying the relevant physical configuration, applying the governing law Given Information Current $I$ or charge $q$ and velocity…
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Problem 3.158 — Magnetostatics and magnetic forces
Problem Statement Solve the magnetic field/force problem: Irodov Problem 3.158 — Magnetostatics and magnetic forces. Key law: $B_{\text{wire}} = \mu_0 I/(2\pi r)$, torque $\tau = mB\sin\theta$, force $F = qvB\sin\theta$ This problem from the Magnetostatics and magnetic forces section requires applying the governing equation with the given geometry and nume Given Information Current $I$ or…