05-01-2018, 04:35 PM
*Whistle used for calling dog
Ans : Galton whistle
*Device used in the studies of sound
Ans : Sonometer
*Device used for recording sound under water
Ans : Hydrophone
* Father of long distance radio transmission
Ans : G-Marconi
Waves
*A disturbance which propagates energy from one place to another without transport of matter
Ans : Wave
*A wave in which the particles of the medium vibrate in a direction perpendicular to the direction of propagation of wave
Ans : Transverse
*A wave in which the particles of the medium vibrate in a direction parallel to the direction of propagation of wave
Ans : Longitudinal wave
*The propagation of disturbances produced on one part of a medium by the vibration of its particles to all other parts
Ans : Wave motion
*The distance between two consecutive particles which are at the same'phase of vibration
Ans : Wave length
*Number of vibrations in one second
Ans : Frequency
*Maximum displacement of a particle from its mean position
Ans : Amptitude
*Waves travelling through layers of earth due to big explosions, earthquakes and volcanic explosions
Ans : Seismic waves
*Scientist dealing with the study of seismic waves
Ans : Seismologist
Laser
*LASER- Light Amplifications by Stimulated Emission of Radiation.
*LASER is a source of intense monochromatic light (only one wavelength or colour).
*LASER was discovered by Theodore Maiman.
*The name LASER was suggested by Gorden Gould.
*LASER beams are used in the medical field to perform minute operations
MASER
* MASER - Microwave Amplification by Stimulated Emission of Radiation.
* MASER was discovered by Charles H.Towns.
RADAR
*RADAR is Radio Detection And Ranging.
*RADAR is a device that uses radio waves to detect the position of objects such as aeroplanes, missile etc.
*Radar was invented by Albert H. Taylor and Leo C. Young.
*Radio signals travel at a speed of 3x10^2 m/s
Electromagnetic Radiation
*The electromagnetic spectrum has electro magnetic waves ranging from - l0^3m - 10^12m
*It includes radio waves, microwaves, infrared, visible region, uv, x-rays and gamma rays.
*Electromagnetic wave with 'maximum wavelength
Ans : Radio waves
*Waves used for communication through satellites
Ans : Microwave
X-rays
*Electro magnetic waves with shorter wave length
Ans : X-rays
*X rays were discovered by Rontgen.
*It is used to study the internal atomic structure of crystals;
*Hard X-rays are of higher frequencies with more penetrating power than soft x-rays.
*Hard X-rays are used in radiations and the treatment of cancer as it penetrates into the body tissues.
*Soft X-rays are used in the photography of internal parts such as chest and bone.
