Class 10 Science - Electricity Concepts & Important Questions

Vocabulary flashcards covering core concepts, formulas, SI units, circuit diagrams, and experimental setups from Class 10 Physics Electricity.

S.I. Unit of Resistivity

The standard unit of electrical resistivity, expressed as Ohm-metre ($\Omega\,\text{m}$).

Electric Current

The amount of electric charge $Q$ flowing through a particular area of cross-section per unit time $t$, mathematically expressed as $I = \frac{Q}{t}$.

Ampere ($\text{A}$)

The S.I. unit of electric current; defined as the current flowing through a conductor when one coulomb of electric charge passes through any cross-section in one second ($1\,\text{A} = 1\,\text{C\,s}^{-1}$).

Conventional Current Direction

The direction of flow of positive charge (from point A to point B), which is conventionally taken as opposite to the direction of flow of negatively charged electrons.

Number of Electrons in One Coulomb

The total count of electrons constituting one coulomb of charge, calculated as $n = \frac{1\,\text{C}}{1.6 \times 10^{-19}\,\text{C}} = 6.25 \times 10^{18}\text{ electrons}$.

Electrical Resistivity ($\rho$)

The resistance offered by a metallic wire of unit length ($1\,\text{m}$) and unit cross-sectional area ($1\,\text{m}^2$), given by the formula $\rho = \frac{R \times A}{l}$.

Factors Affecting Electrical Resistance

The resistance of a conducting wire is directly proportional to its length ($R \propto l$), inversely proportional to its area of cross-section ($R \propto \frac{1}{A}$), and depends on the nature of its material.

Electric Energy

The work done or energy supplied by an electrical source to maintain current flow, given by $E = P \times t = V I t = I^2 R t = \frac{V^2 t}{R}$ with S.I. unit Joule ($\text{J}$).

Electric Power

The time rate at which electric energy is consumed or dissipated by an electrical device, given by $P = \frac{W}{t} = V I = I^2 R = \frac{V^2}{R}$ with S.I. unit Watt ($\text{W}$).

Kilowatt-hour ($\text{kWh}$)

The commercial unit of electrical energy equal to $3.6 \times 10^6\,\text{J}$ ($1\,\text{kWh} = 1000\,\text{Wh} = 1000\,\text{J/s} \times 3600\,\text{s}$).

Ohm's Law

States that the current flowing through a conductor is directly proportional to the potential difference across its ends ($V = IR$), provided physical conditions like temperature remain constant.

Slope of V-I Graph

The slope obtained from plotting potential difference ($V$) against current ($I$), which represents the electrical resistance ($R$) of the conductor at a given temperature.

1 Volt ($\text{V}$)

The potential difference between two points when $1\,\text{joule}$ of work is done in moving $1\,\text{coulomb}$ of charge from one point to another ($V = \frac{W}{Q}$).

Cell or Battery

An electrical source or device that maintains a potential difference across a conductor in a closed circuit.

Series Resistor Network Analysis

A circuit configuration where total equivalent resistance is $R_s = R_1 + R_2$; for $10\,\Omega$ and $20\,\Omega$ in series with a $3\,\text{V}$ source, $R_s = 30\,\Omega$ and current $I = 0.1\,\text{A}$.

Combination Resistor Network Analysis

A network formed by resistors in series and parallel branches where equivalent resistance is given by $\frac{1}{R} = \frac{1}{R_4} + \frac{1}{R_1 + R_2 + R_3}$, yielding $R = 7.5\,\Omega$ for four $10\,\Omega$ resistors.

Resistance Factor Testing Setup

An experimental arrangement with an ammeter, cell, key, and test gap XY used to measure current through wires of differing lengths, cross-sections, and materials.

Ohm's Law Verification Circuit

A circuit layout consisting of a resistance wire, an ammeter in series, a voltmeter in parallel, and a variable number of cells connected across gap XY to measure $V/I$ ratio consistency.