Gaining a Better Understanding of Electricity in CBSE Class 10 Science at Future Classes
This website section provides comprehensive notes on electricity for students of Class 10 CBSE following the NCERT Science syllabus. Our notes cover topics such as electric current, electric circuits, potential difference, power and energy, electromagnetism and more. They provide a clear and concise understanding of the underlying concepts for a better grasp of the subject.
Our website offers a free PDF download of the CBSE Class 10 Science Chapter on Electricity. The file contains comprehensive information on the topics covered under this chapter, including definitions, diagrams and examples. It is a great resource for students to have on hand for studying and revision purposes. The PDF is easy to download and print, so students can refer to it anytime, anywhere. Download now to get access to all the important information about electricity at your fingertips.
CHAPTER 12 ELECTRICITY
Charge
Charge is a fundamental particle in an atom. It may be positive or negative.
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Like charges repel each other.
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Unlike charges attract each other.
S.I. unit of charge is coulomb (C)
Current (I)
​The rate of flow of charge is called current.
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There are two different types of current in use today. They are direct current (DC) and alternating current (AC). In a direct current, the electrons flow in one direction.
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In an electric circuit, when the electric charge is flowing in one direction, the current will flow in the opposite direction.
Electric circuit
The electric circuits are closed-loop or path which forms a network of electrical components, where electrons are able to flow. This path is made using electrical wires and is powered by a source, like a battery.
Potential Difference (V)
Work done to move a unit charge from one point to another point is called the potential difference. S. I. unit of Potential difference is Volt (V)
1 Volt
When 1-joule work is done in carrying one Coulomb charge then the potential difference is called 1 volt.
Ohm’s Law
At constant temperature Potential difference across the two points of a metallic conductor is directly proportional to current.
Resistance (R)
It is the property of a conductor to resist the flow of charges through it.
• Ohm (Ω) is the S. I. unit of resistance.
1 ohm
When the potential difference is 1V and current through the circuit is 1A, then resistance is 1 ohm.
Factors on which the resistance of a conductor depends
The resistance of a uniform metallic conductor is directly proportional to its length (l) and inversely proportional to the area of cross-section (A).
Where ρ (rho) is a constant of proportionality and is called the electrical resistivity or specific resistance of the material of the conductor. The SI unit of resistivity is Ωm.
​The resistance of a conductor depends on the nature of the material of which it is made. Some materials have low resistance, whereas other have high resistance.
Resistivity
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The resistivity of a material does not depend on its length or thickness but depends on the nature of the substance and temperature.
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Insulators such as glass, rubber, etc., have a very high resistivity (1012 to 1017 Ωm), while conductors have a very low resistivity (10-8 to 10-6 Ωm).
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Alloys have higher resistivity than that of their constituent metal. They do not oxidize easily at high temperatures, this is why they are used to make heating element of devices such as electric iron, heaters, etc.,
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Tungsten is almost used exclusively for filaments of electric bulbs, whereas copper and aluminum are generally used for electrical transmission lines.
Resistor
An electrical component with two terminals that are used for either limiting or regulating the flow of electric current in electrical circuits.
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The main purpose of a resistor is to reduce the current flow and to lower the voltage in any particular portion of the circuit.
Resistors in series
When two or more resistors are connected end to end, the arrangement is called a series combination.
Total/resultant/overall/effective resistance in series
The equivalent resistance is thus greater than the resistances of either resistor. This is also known as maximum effective resistance.
PROOF
Resistors in Parallel
Total/resultant/overall/effective resistance in parallel
The equivalent resistance is less than the resistance of either resistor. This is also known as minimum effective resistance.
PROOF
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The voltage across each resistor is the same and equal to the applied voltage.
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The total current is equal to the sum of currents through the individual resistances.
Heating Effect of Electric current
When an electric current passes through a high resistance wire, the wire becomes and produces heat. This is called the heating effect of current.
It is known as joule’s law heating.
Electric bulb
​It has a filament made of tungsten. So, most of the power consumed by this, is dissipated in the form of heat and some part is converted into light because it has high resistivity and high melting point.
Electric fuse
It is used as a safety device in household circuits. It protects the circuits, by stopping the flow of any excessively high electric current. It is connected in series with the mains supply. It consists of an alloy of lead and tin which has suitable melting point.
Formula’s drive
Electric power
It is defined as the amount of electric energy consumed in a circuit per unit time.
The SI unit of electric power is watt (W)
1 watt
Electric power
