CBSE
CLASS 10 SCIENCE
CHAPTER12:ELECTRICITY
NOTES
1. Introduction to Electricity:
👉Electricity is a form of energy resulting from the existence of charged particles (such as electrons and protons).
👉It plays a crucial role in our daily lives and is used to power various electrical appliances and devices.
2. Electric Current:
👉Electric current is the flow of electric charge in a conductor.
👉It is measured in Amperes (A) using an ammeter.
👉Electric current can flow in two ways: direct current (DC) and alternating current (AC).
3. Electric Circuit:
👉An electric circuit is a closed loop or pathway that allows electric current to flow.
👉It consists of a source of electricity (such as a battery or power supply), conductors (wires), and electrical devices (bulbs, resistors, etc.).
4. Symbols Used in Circuit Diagrams:
👉Different electrical components in a circuit are represented by symbols in circuit diagrams.
👉Some common symbols include a cell/battery, resistor, switch, bulb, etc.
5. Ohm's Law:
👉Ohm's law states that the current flowing through a conductor between two points is directly proportional to the voltage across the two points, and inversely proportional to the resistance between them.
👉Mathematically, Ohm's law is expressed as: V = I × R, where V is the voltage, I is the current, and R is the resistance.
👉Ohm's law helps in understanding the relationship between voltage, current, and resistance in a circuit.
6. Factors Affecting Resistance:
👉Resistance is a property of a material that opposes the flow of electric current.
👉The factors affecting resistance include the length of the conductor, its cross-sectional area, and the nature of the material (resistivity).
👉Longer conductors have higher resistance, while wider conductors have lower resistance.
👉Materials with higher resistivity offer more resistance to the flow of current.
7. Series and Parallel Circuits:
👉In a series circuit, the components are connected end to end, forming a single path for the current to flow.
👉In a parallel circuit, the components are connected in separate branches, providing multiple paths for the current to flow.
👉In a series circuit, the total resistance is the sum of individual resistances, while in a parallel circuit, the total resistance is less than the smallest resistance.
8. Electric Power:
👉Electric power is the rate at which electrical energy is consumed or produced in an electric circuit.
👉It is measured in Watts (W) and is calculated using the formula: P = V × I, where P is the power, V is the voltage, and I is the current.
9. Effects of Electric Current:
👉Electric current produces various effects, including heating effects, magnetic effects, and chemical effects.
👉The heating effect of electric current is utilized in devices like electric heaters and electric irons.
👉The magnetic effect of electric current is the basis for the working of electromagnets and electric motors.
👉The chemical effect of electric current is used in electrolysis, where chemical reactions are facilitated by passing an electric current through a solution.
10. Safety Measures:
👉While working with electricity, it is essential to take safety precautions to avoid accidents or electric shocks.
👉Some safety measures include using proper insulation, avoiding contact with live wires, switching off the power supply before handling electrical components, etc.
⭐These are some key points and concepts covered in Class 10 NCERT Science Chapter 12: Electricity. It is advisable to refer to your NCERT textbook for a more detailed understanding and additional information on the topic.