Physics 7

പ്രധാനപ്പെട്ട വേവ്സ്, റെയ്‌സ്, റഡാർ, എന്നിവ കൂടാതെ താപവുമായി ബന്ധപ്പെട്ട ചോദ്യങ്ങളുമാണ് ഇന്നത്തെ പാഠത്തിൽ ഉൾപ്പെടുത്തിയിരിക്കുന്നത്

• Waves used in point to point fixed telecommunication

                       Microwaves

• Waves used in Radio and Television communication

                       Radio waves

• Electro magnetic waves having lowest frequency

                       Radio waves

• Rays which cause sunburn

                       Ultraviolet Rays

• LASER stands for

                       Light Amplification by Stimulated Emission of Radiation

• LASER was discovered by

                       Theodore Maiman

• Rays used in Medical field for performing minute operations

                       LASER

• MASER stands for

                       Microwave Amplification by Stimulated Emission of Radiation

• MASER was discovered by

                       Charles H Towns

• RADAR stands for

                       Radio Detection and Ranging

• Device used to detect the position of objects like Aeroplanes, missile etc using Radio Waves

                       RADAR

• RADAR was detected by

                       Albert H Taylor and Leo C Young

• Father of long distance Radio transmission

                       Marconi

• Intensity of sound of Thunder storm

                       110 db

• Intensity of sound of Jet Take off

                       130 db

• A disturbance which propagate energy from one place to another without transport of matter

                       Wave

• Propagation of disturbance at one place by vibration  of particles to all other parts 

                       Wave Motion

• A wave in which particles of medium vibrate in perpendicular to the direction of propagation of wave

                       Transverse wave

• A wave in which particles of medium vibrate in parallel to the direction of propagation of wave

                       Longitudinal wave

• The distance between two consecutive particles which are at the same phase of vibration

                       Wave length

• No of vibrations in one second

                       Frequency

• Maximum displacement of a particle from its mean position

                       Amplitude

• Waves travelling through layers of earth due to Earthquakes, big explotions, volcanic explotions

                       Seismic Waves

• Scientists dealing with the study of seismic waves 

                       Seismologist

• Transfer of Kineti Energy from one medium or energy source to another medium is

                       Heat

• The study of materials and Phenomena at low temperature

                       Cryogenis

• Form of energy that gives us the sensation of hotness or coldness

                       Heat

• The degree of hotness or coldness of a body is defined as 

                       Temperature

• Unit other than Joule using to measure Heat

                       Calorie

• One calorie

                       4.2 Joules

• The amount of heat required to raise the temperature of 1 gm of water by 1 degree C

                       One Calorie

• As we go up the atmosphere, the temperature

                       Decreases

• Color which absorbs more heat

                       Black

• Device used to detect heat radiation is called 

                       Thermocouple

• The amount of heat required to raise the temperature of unit mass of a substance by 1°C  

                       Specific Heat Capacity

• Substance having highest specific heat capacity  

                       Water (4185 J/KgK)

• Specific heat of water is minimum at

                       37°C

• Element having highest specific heat capacity  

                       Hydrogen

• Temperature above which a gas cannot be liquified even in more power is called

                       Critical temperature

• Temperature at which Ice melts

                       0°C or 273K or 32°F

• Temperature at which water boils

                       100°C or 373K or 212°F

• Absolute zero is

                       -273.15°C or 0K

• Temperature which shows same temperature in Fahrenheit scale and Celsius scale

                       -40

• Temperature which shows same temperature in Fahrenheit scale and Kelvin scale

                       574.25

• Fraction of volume of ice seen outside when it is immersed in water

                       10.5%

• Various temperature scales are

                       Celsius (C), Kelvin (K), Fahrenheit (F), Rankine (Rn)

• Pressure of a gas is reduced to zero at

                       -273.15°C

• In Fahrenheit scale the interval between ice point and boiling point is devided into

                       180 equal parts

• To convert Celsius into Fahrenheit

                       F= (Cx9/5)+32

• To convert Fahrenheit into Celsius

                       C= (F-32)x5/9

• To convert Celsius into Kelvin scale

                       K= C+273.15

• To convert Kelvin into Celsius scale

                       C= K-273.15
                                                                                   (To be Continued...)