Electric Current

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Electric current is the ordered motion of charges. It is defined as the amount of charge crossing any cross section of a conductor in one second. Formula: I = Q/t, where I is current (ampere), Q is ch…

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The SI unit of electric current is ampere (A). 1 Ampere = 1 coulomb/1 second. This means 1 ampere current flows when 1 coulomb of charge passes through a cross-section in 1 second.

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Random motion: In an open circuit, electrons move randomly in all directions with no net charge flow. Drift motion: When connected to a battery, electrons move in an ordered direction (towards positiv…

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Potential difference is the work done by electric force on unit positive charge to move it through a distance from point A to B. Formula: V = W/q, where V is potential difference (volt), W is work don…

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Ohm's Law: The potential difference between the ends of a conductor is directly proportional to the electric current passing through it at constant temperature. Mathematical expression: V = IR, where …

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Resistance is the obstruction offered to the motion of electrons in a conductor. It is the property of a material that opposes the flow of current. SI unit: Ohm (Ω). 1 Ohm = 1 Volt/1 Ampere.

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The resistance of a conductor depends on: 1. Length (R ∝ l) - directly proportional, 2. Cross-sectional area (R ∝ 1/A) - inversely proportional, 3. Nature of material (resistivity), 4. Temperature of …

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R = ρl/A, where R = resistance (Ω), ρ = resistivity (Ω-m), l = length of conductor (m), A = cross-sectional area (m²). Resistivity (ρ) is a material property that determines how strongly it opposes cu…