Chapter 4: Effects of Electric Current Notes – Class 10 Science (MSBSHSE)

This in-depth guide to Effects of Electric Current covers all important phenomena—heating, magnetic, chemical—as well as formulas, circuit diagrams, solved examples, and board-focused tips. Ideal for SSC exam preparation!

🔹 1. What is Electric Current?

Electric current is the flow of electric charge, measured in ampere (A). In metals, this is due to the movement of electrons; in electrolytes, it's ions.

🔹 2. Heating Effect of Electric Current

🔸 Joule's Law of Heating

A current through a resistor produces heat, given by:

H = I² × R × t

• H: Heat (Joules), I: Current (A), R: Resistance (Ω), t: Time (s)

🔸 Applications

• Electric heaters, bulbs, toasters
• Fuses in circuits melt to prevent overcurrent damage

🔹 3. Magnetic Effect of Electric Current

🔸 Magnetic Field around a Current

A current-carrying conductor generates a magnetic field. The right-hand thumb rule shows its direction.

🔸 Electromagnets

• Coiled wire around iron core, current → powerful magnet
• Used in motors, relays, MRI machines

🔸 Fleming’s Left-Hand Rule

Used to find direction of force in motors: thumb = motion, forefinger = field, middle finger = current.

🔹 4. Chemical Effects of Electric Current

Electric current in electrolytic solution causes electrolysis. Ions move to electrodes:

• Cathode (–): positive ions gain electrons (reduction)
• Anode (+): negative ions lose electrons (oxidation)

🔸 Example: Electrolysis of Copper Sulfate

Cathode: Cu²⁺ + 2e⁻ → Cu (deposit)
Anode: Cu → Cu²⁺ + 2e⁻

Used for electroplating and purification.

🔹 5. Electric Power and Energy

Electric power consumed by a device:

P = V × I = I² × R = V² / R

• P: Power (W), V: Voltage (V), I: Current (A)

Energy consumed = P × t (in watt-hours or kilowatt-hours)

🔹 6. Series and Parallel Circuits

• Series: I same, total R = R₁ + R₂ + …
• Parallel: V same, 1/R_total = 1/R₁ + 1/R₂ + …

Use diagrams to show how bulbs vary in brightness in each setup.

🔹 7. Solved Numerical Examples

1. Current through 5 Ω resistor at 2 A → Power = I²R = 4 × 5 = 20 W
2. Energy consumed by 100 W bulb for 5 hours → E = 100 × 5 = 500 Wh = 0.5 kWh
3. Three 10 Ω resistors in parallel → R_total = 10/3 Ω, current at 6 V → I = 1.8 A

🔹 8. Important Definitions & Terms

• Resistor: Limits current
• Fusible wire: Safety device for overload protection
• Electrolysis: Chemical change by electricity
• Ohm’s Law: V = I × R

🔹 9. Exam Tips (Last 5 Years)

• Define and give real-life examples of each effect
• Draw motor and fuse circuits with labels
• Solve current-power-energy numericals accurately
• Balance equations for electrolysis and describe electrodes

🔗 You may also like:

• Chapter 1: Gravitation
• Chapter 2: Periodic Classification of Elements
• Chapter 3: Control and Coordination
• Class 10 Kumarbharati Textbook Solutions
• Class 10 All Subject Notes
• Class 10 English Paper Pattern

📘 Continue learning! Chapter 5 up next—keep checking for updates.