Pandey Sir BEST Classes

BEST = Bright & Energetic Students Tuition

Class 10 Science Electricity notes card
Class 10 Science

Class 10 Science Chapter 11 Electricity — Best Notes

Pandey Sir

Introduction to Electricity

Electricity is the backbone of modern life. For CBSE Class 10 students, Chapter 11: Electricity is a crucial part of the Physics syllabus. These notes cover the fundamental concepts of electric charge, current, potential difference, resistance, and their practical applications.

Important Mind Map

CBSE Class 10 Electricity Chapter 11 Formulas and Notes by Pandey Sir's Best Classes.

1. Fundamental Concepts & Formulas

Electric Charge (Q)

Electric charge is the property of matter that causes it to experience a force in an electromagnetic field.

  • SI Unit: Coulomb (C)
  • Formula:Q=n×e
    • (Where e=1.6×10−19C is the charge of one electron)
  • Key Rule: Like charges repel; unlike charges attract.

Electric Current (I)

Current is defined as the rate of flow of electric charge through a conductor.

  • SI Unit: Ampere (A)
  • Formula:I=Qt
  • Measurement: Measured using an Ammeter (always connected in Series).

Potential Difference (V)

Potential difference (Voltage) is the work done to move a unit charge from one point to another.

  • SI Unit: Volts (V)
  • Formula:V=WQ
  • Measurement: Measured using a Voltmeter (always connected in Parallel).

2. Ohm’s Law & Resistance (High Priority Topic)

Ohm’s Law states that at a constant temperature, the current flowing through a conductor is directly proportional to the potential difference across its ends.

  • Formula:V=I×R
  • Graph: The V-I graph is a straight line passing through the origin.

Factors Affecting Resistance

Resistance (R) is the property to oppose current flow. It depends on:

  1. Length (L): R∝L (Directly proportional)
  2. Area (AA): R∝1/A (Inversely proportional)
  3. Temperature: R∝T (For metals)

3. Heating Effect & Power

Joule’s Heating Effect

When current flows through a resistor, heat is produced due to electron collisions.

  • Heat Formula: H= I2Rt (I square x R x t)

Electric Power (P)

The rate at which electrical energy is consumed.

  • SI Unit: Watt (W)
  • Formula:
    1. P = V×I

Commercial Unit of Energy

  • Unit: Kilowatt-hour (kWh)
  • Conversion: 1 kWh=3.6×106 Joules1 kWh=3.6×106 Joules

Electric Fuse

A safety device made of an alloy (Lead-Tin) with a low melting point. It protects circuits from overloading and short-circuiting by melting when the current exceeds the rated value.

Q1: What is the SI unit of Electric Current?

Ans: The SI unit of electric current is the Ampere (A).

Q2: How should an ammeter be connected in a circuit?

Ans: An ammeter must always be connected in SERIES because it has very low resistance and should not alter the current flowing through the circuit.

Q3: Why are domestic appliances connected in parallel?

Ans: Parallel connection is used in homes because:
1. Each appliance gets the full voltage (220V).
2. Each appliance can be turned on/off independently.
3. If one appliance fails, others continue to work.

Q5: What happens to the resistance if the length of the wire is doubled?

Ans: Since resistance is directly proportional to length (R∝L), if the length is doubled, the resistance also doubles.

Numerical: Q1. A potential difference of 10 V is applied across a 5 ΩΩ
 resistor. Calculate the current flowing through it.

Solution:
Given: Voltage (V) = 10 V, Resistance (R) = 5 Ω
Formula: From Ohm’s Law, 
I=V/R
Calculation: 
I=10/5

Answer: Current (I) = 2 A

Practise Electricity