the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other is known as _______
friction
Supporter of Combustion
Oxygen
The male gametes of humans are
sperms
The type of friction which is the strongest friction
Static friction
the angle of incidence and angle of reflection of light is _________
equal
The number of oscillations per second (chapter-Sound)
frequency
The substances undergoing combustion are termed as combustible substances or ________
fuels
The process of removing the chaff from grains
threshing
The light ray that comes back from the surface after reflection is known as the ____________
Reflected ray
Petrol and Diesel are obtained from a natural resource called ________
Petroleum
Audible sound for human (range in Hz) is ___________
20Hz-20000Hz
Calorific value of(in kj):(100 for each correct)
1)Kerosene
2)Methane
3)Hydrogen
Kerosene-45000kj
Methane-50000kj
Hydrogen-150000kj
Animals reared at home or farm on a large scale is known as ________
Animal Husbandry
The light ray which strikes any surface is called the ____________
Incident Ray
An electroscope is a device which is used to find if an object is __________.
a)Magnetic
b)Charged
c)Hot
b)Charged
The force that acts on an object due to the earth's gravitational pull is called
Weight
The British chemist who discovered electrolysis of water
William Nicholson
Four major groups of microorganisms are
Bacteria, fungi, protozoa, algae
The black, thick liquid with an unpleasant smell, a mixture of about 200 substances. It is __________
coal tar
The earth's plate responsible for causing earthquakes is _____________
the crust of the earth
Pressure exerted by a gas depends on ___________
volume and temperature (250 for each correct)
The reaction at cathode and anode during electrolysis of water(chemical reaction)(chemical equations)
cathode:2H+-2E- = H2
anode:4OH--4E- = O2+2H2O
Robert Koch in 1876 discovered the bacterium ______ which causes ________ disease.
1(Bacillus anthracis)
2 (anthrax)
A tough, porous and black substance which is almost a pure form of carbon and is used in the manufacture of steel and in the extraction of many metals. It is ________
coke
The boundaries of the earth's plate is known as
Seismic Zone
Fault Zone
(250 point for each correct)