(CAR) Physics 2 Flashcards
The Hydraulic brakes used in automobiles is a direct application of
Pascal’s Law
Why does the mercury column in the barometer fall rapidly before a severe storm
It is due to the fall in atmospheric pressure
The speed of sound is maximum through which of the following
Glass
Echo is the effect produced due to
Reflection of sound
why are transfomers used in the transmission of electric power?
Because they can reduce transmission losses
A mixture of ____ and ____ is used in the manufacture of electric bulbs
Oxygen and Argon
Salty water has _____ density
Higher
____ is used for detecting and measuring small electric currents
Galvanometer
the lightning conductor of rod used for protecting buildings from lightning is made of
Copper
What is the melting point of Tungsten?
3000 degree celecius
3,422 °C
Why is the light of ordinary lamp hotter than tubelight
It is due to incandescence
The resistance of a bulb rated 60 watts/ 220 volts is approx
800 (Horse Shoe)
Sonar works on the principle of
Reflection of Sound
A plant with green leave’ ?s placed in red light will appear
Black
The common refrigent used in the domestic refrigerator is
Freon/ Ammonia
Who said, ‘A body will remain at rest unless an external force acts on the body’?
Newton
Which metal is commonly used as an electormagnet
Iron
_____ does not admint any division
Atom
The dynamo converts
Mechanical energy into electrical energy
A red light is used in a traffic signal becuase
It has the longest wavelength and can be easily noticed from a distance
Metals are good conductors of electricity coz
The contain free electrons
In diesel engines ignition takes place by
Compression
Cloudy nights are warmer coz
Clouds prevent radiation of heat from ground to air
If we go to the Himalayas, we feel breathless coz
The density of air is much less on the hills so oxygen content is reduced
In deserts clouds do not precipitate coz
Low humidity
Ultrasonic Waves?
Sound waves having high frequency higher than audio-frequency range
A radar which detects the presence of an enemy aircraft uses
Radiowaves
Fish plates are used in railway tracks
To control the speed of the train
A fuse wire is used to
Prevent an unduly high electric current to pass through a circuit
A molecule is
The smallest unit of a substance that retains the properties of the substance
The nucleus of an atom consists of
Proton and Neutrons
In what order does the velocity of sound increases in different media
Air, Water and Iron
Sound travels with a diff speed in diff media
_____ metal is used in aircraft
Palladium
Platinum and palladium are used because they are stable, corrosion-resistant and durable.
During rusting
Iron gains weight
Rectifiers are used to convert
AC to DC
Phenomenon of formation of three dimensional image by interference of two light beams from laser or other coherent source of light is called
Holography
Paper becomes brittle and yellow with age, Why?
- The acid cosenntent in paper causes brittleness to develop.
- In the presence of light, Photosensitised oxidation occurs.
- The ultra violet component of sunlight causes photolysis of cellulose by direct cleavage of the cellulose polymer
____ is used as a coolant in nuclear reactors
Liquid Sodium
____ is good nuclear fuel
Plutonium-239
In atomic explosion, enormous energy is released which is due to the
Conversion of mass into energy
_____ and ___ take place when the subject speaks untruth while being tested by the polygraph instrument
- His blood pressure goes up
- His pulse quickens
Aviation fuel for jet aeroplanes consists of purified
Kerosene
A small weight is put on the pressure cooker. It increases the pressure of the steam coz
Bernoulli’s principle
When an electric bulb breaks, there is a mild bang due to
The air rushing in to fill the evacuated space
Kinetic energy depends
Both mass and velocity of the moving body
The diff b/w a nuclear reactor and an atomic bomb is that
The chain reaction in nuclear reactor is controlled
A ship rises as it enters the sea from a river coz
Density of sea water is higher than that of the river water
Why is a cyclist required to bend inwards while moving inn a circular parth
To produce the neccsary centripetal force required to keep him moving in a curved path
Heat recived by earth from the sun is known as
Solar radiation
Special theory of relativity was proposed by
Einstein
(theory of special relativity, determined that the laws of physics are the same for all non-accelerating observers, and he showed that the speed of light within a vacuum is the same no matter the speed at which an observer travels)
Isaac Newton gave
Laws of motion and laws of Gravitation
He was British
