Current Electricity — Flashcards

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Electric current (I) is defined as the rate of flow of electric charge through a cross-sectional area of a conductor. It is given by I = dQ/dt. SI unit: Ampere (A). 1 Ampere = 1 Coulomb/1 second. This…

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Given: Charge (Q) = 120 C, Time (t) = 1 minute = 60 seconds. Using formula: I = Q/t. Step 1: I = 120 C / 60 s. Step 2: I = 2 C/s. Step 3: I = 2 A. Answer: The electric current is 2 amperes.

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Conventional current flows from the positive terminal to the negative terminal of a battery (direction a positive charge would move). Electron flow is the actual movement of electrons from the negativ…

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Drift velocity is the average velocity acquired by free electrons in a conductor when subjected to an electric field. It is calculated as: vd = eτE/m, where e is electron charge, τ is mean free time, …

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Given: Cross-sectional area (A) = 0.5 mm² = 0.5 × 10⁻⁶ m², Current (I) = 0.2 A, Free electron density (n) = 8.4 × 10²⁸ m⁻³, Electron charge (e) = 1.6 × 10⁻¹⁹ C. Using formula: vd = I/(neA). Step 1: vd…

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Microscopic Form: J = σE, where J is current density (A/m²), σ is conductivity (S/m), and E is electric field (V/m). This relates current density to electric field in a material. Macroscopic Form: V =…

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Given: Potential difference (V) = 12 V, Resistance (R) = 24 Ω. Using Ohm's Law: I = V/R. Step 1: I = 12 V / 24 Ω. Step 2: I = 0.5 A. Answer: The current through the resistor is 0.5 amperes.

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Resistance (R) is the opposition offered by a material to the flow of electric current through it. It depends on the material's nature, length, and cross-sectional area. Formula: R = ρl/A. Resistivity…