Force, Work, Power and Energy
Work, Power and Energy
Refraction of Light Through Plane Surface
Refraction of Light Through a Lense
Electricity and Magnetism
Electrical Power and Energy and Household Circuits
- Concept of Electrical Power and Household Circuits Numericals
- Household Circuits - Colour Coding of Wires
- Household Circuits - Three-pin Plugs
- Household Circuits - Safety Precautions
- Earthing (Grounding)
- Electric Switch
- Household Circuits – Main Circuit
- Electrical Energy and Power
- Electric Power
- Alternating Current (A.C.) Generator
- Current Electricity
- Resistors in Series
Reflection of sound:
Sound can bounce off a solid or a liquid. Some materials like metals and walls are called Good Reflectors of Sound as they do not absorb the sound while others like clothes and sponge are called Bad Reflectors of Sound as they absorb the sound easily.
Laws of reflection
There are two basic laws of reflection of sound:
(i) Angle of incidence is equal the angle of reflection.
(ii) The incident wave, the reflected wave and the normal all lie in the same plane.
Applications of Reflection of Sound
Uses of multiple reflection of sound:
- Horns, trumpets, loudhailers or megaphones are designed in such a way that sound can travel in a particular direction only without spreading out everywhere. This makes it easier for the audience to listen to the speaker. All these instruments work on the phenomena of multiple reflections of sound.
- Stethoscope is a medical instrument used for listening to sounds produced within the body, mainly in the heart or lungs. In stethoscopes the sound of the patient’s heartbeat reaches the doctor’s ears by multiple reflection of sound
- Generally the ceilings of concert halls, conference halls and cinema halls are curved so that sound after reflection reaches all corners of the hall, Sometimes a curved soundboard may be placed behind the stage so that the sound, after reflecting from the sound board, spreads evenly across the width of the hall.