A loudspeaker converts electrical signals into sound waves using electromagnetic principles. It consists of a coil, a permanent magnet, and a conical diaphragm. When an electric current flows through the coil, it interacts with the magnet's field, causing the diaphragm to vibrate. These vibrations create compressions and rarefactions in the air, generating sound waves that we can hear.
Topics
Living World and Classification of Microbes
Health and Diseases
Force and Pressure
Current Electricity and Magnetism
Inside the Atom
Composition of Matter
- Matter (Substance)
- Characteristics of Particles (Molecules) of Matter
- States of Matter
- The Solid State
- The Liquid State
- The Gaseous State
- Elements
- Earth and Elements
- Non-Metals
- Type of Element: Metalloid
- Compound
- Types of Compound
- Mixture
- Types of Mixtures
- Introduction to Solutions
- Suspension Solution
- Colloidal Solution
- Molecular Formula of Compounds
- Periodic Trends in the Modern Periodic Table
Metals and Nonmetals
Pollution
- Pollution
- Air Pollution
- Prevention and Control of Air Pollution
- Water Pollution
- Effects of Water Pollution
- Prevention and Control of Water Pollution
- Soil Pollution
- Effects of Soil Pollution
- Prevention and Control of Soil Pollution
- Relationship of Soil Pollution with Air and Water Pollution
- Laws for Control, Regulation, and Prevention of Pollution by Indian Government
Disaster Management
Cell and Cell Organelles
- Cell: Structural and Functional Unit of Life
- Prokaryotic and Eukaryotic Cell
- Plant Cell Vs Animal Cell
- Cell Organelles
- Structure of the Cell > Cell Wall: “Supporter and Protector”
- Structure of the Cell > Plasma Membrane / Cell Membrane
- Structure of the Cell > Cytoplasm: “Area of Movement”
- Structure of the Cell > Nucleus: “Brain” of the Cell
- Endoplasmic Reticulum (ER)
- Golgi Apparatus - "The delivery system of the cell"
- Lysosome - “Suicidal Bag”
- Mitochondria - “Power House of the Cell”
- Plastids
- Non-living Substances Or Cell Inclusion
Human Body and Organ System
- Human Body
- Human Organ System
- Mechanism of respiration-Breathing
- Human Respiratory System
- Blood Circulatory System
- Human Heart
- Blood Vessels
- Circulation of Blood in the Heart (Functioning of Heart)
- Heart Beat
- Blood
- Composition of Blood > Plasma (The Liquid Portion of Blood)
- Composition of Blood > Cellular Elements: Red Blood Cells (Erythrocytes)
- Composition of Blood > Cellular Elements: White Blood Cells (Leukocytes)
- Composition of Blood > Cellular Elements: Blood Platelets (Thrombocytes)
- Functions of Blood
- Blood Transfusion and Blood Groups (ABO and Rh system)
- Blood Pressure (B.P.)
- Heart Related Conditions
Introduction to Acid and Base
Chemical Change and Chemical Bond
Measurement and Effects of Heat
Sound
Reflection of Light
Man Made Materials
Ecosystems
Life Cycle of Stars
- Introduction
- Parts of a Loudspeaker
- Working of a Loudspeaker
Maharashtra State Board: Class 8
Introduction:
Maharashtra State Board: Class 8
Parts of a Loudspeaker:
- Permanent Magnet: A fixed magnet inside the loudspeaker that creates a magnetic field.
- Coil: A wire wound around a core near the permanent magnet. When electric current flows through this coil, it produces a magnetic field.
- Conical Screen (Diaphragm): A lightweight, cone-shaped screen attached to the coil. This screen vibrates to generate sound waves.
- Input Signal: Electrical signals from a microphone or other audio source are sent to the loudspeaker.
Internal construction of a loudspeaker
Maharashtra State Board: Class 8
Working of a Loudspeaker:
- When an electric current flows through the coil, it produces a magnetic field around the coil. This magnetic field interacts with the field of the permanent magnet.
- Depending on the direction and strength of the current, the coil is either attracted to or repelled by the permanent magnet. This causes the coil to move back and forth.
- The coil is attached to the conical screen (diaphragm), so as the coil moves, the screen also moves back and forth.
- These vibrations generate sound waves in the surrounding air, similar to how a tuning fork produces sound.
- The frequency of the screen’s vibration determines the pitch of the sound and the amplitude of the screen’s vibration determines the loudness of the sound.
Generation of Sound Waves,
- The back-and-forth motion of the diaphragm compresses and rarefies the air molecules around it. This creates sound waves that propagate through the air to reach our ears.
- These vibrations can be felt by gently touching the diaphragm of a working loudspeaker.
Very loud sounds can be produced using a loudspeaker, which is why they are commonly used in public places. However, as we learnt last year, sound levels around 100 decibels can be harmful to human hearing. Although loudspeakers can generate very loud sounds, there should be a limit on their loudness.
