Physics: Electric Current and Circuits

In a series circuit, components are connected one after the other, and the overall resistance is the sum of individual resistances. In a parallel circuit, components are connected between the same two points, and the overall resistance is less than the individual resistances. The parallel circuit reduces the overall resistance, making it more efficient.

R = ρ × L / A, where ρ is the inherent property of the material, L is the length of the conductor, and A is the cross-sectional area. The significance of each variable is that ρ depends on the material and temperature, L affects the overall resistance, and A affects the amount of current that can flow.

Electric power (P) is the rate of energy transfer, and energy (E) is the total work done in a circuit. The relationship between them is E = P × t, where t is time. This means that the energy transferred in a circuit is equal to the power multiplied by the time over which it is transferred.

<p>Drift velocity is the average velocity of electrons in a conductor, and mobility is the ease with which electrons move through a conductor. The mobility (μ) is related to the drift velocity and is given by μ = (e / m) × τ, where e is the elementary charge, m is the electron mass, and τ is the relaxation time.</p> Signup and view all the answers

<p>Kirchhoff's Current Law (KCL) states that the sum of currents entering a node is zero. This law is used to analyze complex circuits by applying it to each node, allowing the calculation of unknown currents and voltages.</p> Signup and view all the answers

<p>The Wheatstone bridge circuit consists of two branches: one with known resistance and one with unknown resistance, and a galvanometer. The bridge is balanced by adjusting the known resistance until the galvanometer reads zero. This allows the measurement of small changes in resistance.</p> Signup and view all the answers

<p>The relationship between voltage, current, and resistance is expressed mathematically as V = I × R, which is Ohm's Law. This law states that the voltage across a conductor is equal to the product of the current flowing through it and its resistance.</p> Signup and view all the answers

<p>Electric current is the flow of electrons from higher to lower potential. In a circuit, electrons flow from the negative terminal of the source, through the conductor, and back to the positive terminal. The conductor provides a path for the electrons to flow, and the flow of electrons is facilitated by the electric field.</p> Signup and view all the answers

<p>The resistivity (ρ) of a material is its inherent property that determines its opposition to electric current flow. It affects the overall resistance of a conductor by being a factor in the formula R = ρ × L / A, where R is the resistance, L is the length, and A is the cross-sectional area.</p> Signup and view all the answers

<p>Energy is transferred in an electric circuit through the flow of electrons, which is facilitated by the electric field. The relationship between power and energy is E = P × t, where t is time. This means that the energy transferred is equal to the power multiplied by the time over which it is transferred.</p> Signup and view all the answers