# Electricity class 10 notes

## Introduction to Class 10 Electricity

Class 10 science chapter 12 Electricity aims to answer questions like “What is electricity?”, “What are the factors that regulate or control the flow of electricity” and “How does electricity flow in an electrical circuit”. We also discuss the heating effects of electricity and their applications. We will also discuss the atomic structure of electric current in our efforts to understand its composition. Also read Character Sketch of Bholi

## Atomic Structure

• An atom is composed of a positively charged nucleus, and negatively charged electrons that revolve around it.
• The conductor is free to allow valence electrons from metals to flow within it and create an electric current.

### Charge

The charge is an intrinsic property that makes matter possible to exert electromagnetic force. ## Insulators and conductors

Conductors are substances that offer comparatively low resistance to current flow. Insulators, on the other hand, are substances that offer greater opposition. Copper, iron, and steel are examples of conductors. Glass, dry wood, and cotton are some examples of insulators.

### Electric Potential and Potential Difference

An electric potential is the amount of work required to bring a unit positive charge from zero to one point. The difference in the electric potentials at two points is the potential difference. The potential difference is the difference in electric pressure between two points. Electrons can only move if there’s a difference in that electric pressure. One Volt refers to energy consumed of 1 joule for each electric charge of 1 coulomb.

Mathematically, the electric potential between two points can be expressed as:

V=W/Q

V is the potential difference. W is the work done. Q is the electric charging.

### Electric Current(I).

Electric current is the flow of electric charges.

## Models of Electric Current

### Drift velocity for Electron

The average velocity that an electron achieves within a metallic conductor is due to the application an electric field due the potential difference. ### Battery and its working

A cell is a source for potential difference. This is due to internal chemical reactions. Anode: Cu(s),=Cu2+ (aq)+2e
At cathode: Ag(aq)+2e=2Ag(s).
A battery is a combination of cells.

## Electric Circuit

### Circuit diagram and electric circuit

• An electric circuit is a closed loop path that a current follows.
• A circuit diagram is a representation of an electric circuit using symbols. ## Resistance and Ohm’s Law

### Ohm’s law

The applied potential difference between the conductor’s ends determines the current flow through an ohmic conductor. Ohm’s Law describes the relationship between potential difference across conductors and current flowing through them ### Resistance

Resistance refers to the resistance that is applied to an electric circuit’s current flow. In ohms, resistance is measured. All materials can resist current flow to a certain degree. All materials can be classified into one of two categories: Insulators or Conductors.

### Factors that affect Resistance and How they Affect

Resistance is:

• Directly proportional to length of conductor.
• Directly proportional to the conductor’s nature
• Directly proportional to temperature of conductor
• The conductor’s cross-sectional area is inversely proportional.

This is mathematically represented as:

R=PL/A

### Resistivity

Resistivity is the electrical resistance that a substance with unit length and unit cross sectional area offers to electricity.

hr=RA/l

Ohmic and Non Ohmic resistors

Ohmic resistors are those that follow Ohm’s Law. Those who don’t follow it are called Non Ohmic resistors. ### Superconductors

Superconductors are conductors that offer no resistance to current flow. Aluminium, niobium and magnesium diboride are some of the most prominent superconductors.

## Combination of Resistors

### Combination resistors

• If they are carrying the same current, two resistors can be considered to be in series.
• If they have the same potential difference, two resistors can be combined in parallel.

### Equivalent Resistance to a System of Resistors

This is the equivalent resistance of two resistors:

• Req=R1+R2 in series
• Parallel, 1/Req=1/R1+/1/R2 ### EMF, Terminal Voltage

• EMF is the potential difference between two terminals of a cell when there is no current flowing through it.
• Terminal voltage: A potential difference between two terminals of a cell when current flows through it. ## Electric Power and AC

### Heating Effects of Current

Joule’s Law:

• Heat (H) squared of the current (I).
• H Resistance of the given circuit.
• H Time (t) at which current flows through conductor.

Potential differences are what cause electrons to move when they are established. flow of current.

### Heating Effects of Electric Current

Electric heating appliances, such as electric iron, electric kettle, and electric iron, use the heating effect of current to heat water.
is a website that provides information about heating effects of current.

### Electric Power

• Electric Power is the rate at which you do work or consume electrical energy. If W is the work done in timet, then P=W/t.
• S.I unit is Watt(W). One watt is used when 1 A of current flows at 1 V potential difference.
• A kilowatt-hour (kWh) is the commercial unit for electrical energy.
• 1kWh = 3,600,000J = 3.6x106J
• Represented as: P=I2R or P=V2/R
• One kilowatt hour is the energy used when 1kW of power has been used for an hour. error: Content is protected !!