The principle on which a Jet engine works is
conservation of mass
Newtonian law of action and reaction
conservation of angular momentum
None of the above
Correct Answer :
B. Newtonian law of action and reaction
Related Questions
When are temperature resistance
increases
decreases
remains the same
first increases then decreases
Isotones are species of atoms containing
same number of protons but different number of neutrons
same number of neutrons but different number of protons
the same total number of protons and neutrons
same number of protons and different number of electrons
The planet that moves fastest around the sun is
Mars
Venus
Earth
Mercury
No current will flow between two charged bodies if they have the same
resistance
charge
potential
charge/potential ratio
The first Indian Satellite launched from a Russian Cosmodrome on April 16, 1975 was named
Bhaskara
Insat I-A
Aryabhatta
SLV-l
The attraction of unlike molecules at the common surface is known as
adhesion
cohesion
surface tension
capillarity
The tiniest of the stars belong to the group known as
Giant stars
White Dwarf stars
Neutron stars
Super-giant stars
Holography is the technique of
taking photos of various objects
recording and reproducing three dimensional images
tracing out planets and stars in the sky
transmitting light waves
In a dynamo
mechanical energy is converted to light energy
mechanical energy is converted to heat energy
mechanical energy is converted to electrical energy
electrical energy is converted to mechanical energy
Primary colours are
colours of the rainbow
colours in the spectrum of white light
colours which cannot be produced by mixing other colours
colours found in nature
Who first established the fact that the earth revolves round the sun?
Sir Isaac Newton
Kepler
Copernicus
Ptolemy
Cyclotron is an apparatus used
as an accelerator for imparting energies to charged particles of atomic magnitudes
to reduce the charge on a particle
to produce intense magnetic field
to produce intense electrical field
The study of astronomy include a
astrology
astrophysics
astrometry
Both (b) and (c) above
For viewing objects placed at a higher level from a position at a lower level, the instrument used' Is known aa
telescope
spectrometer
microscope
periscope
Which of the following is wrongly matched?
electric current - ampere
resistance - Ohm
electric power - volt
electric charge Coulomb
A permanent magnet may be demagnetised by
placing it inside a solenoid through which an alternating current is flowing
heating the magnet to redness and then allowing it to cool
dropping it several times or hammering it while lying east-west
All the above
The extremely luminous objects located at the centre of some distant galaxies and which are sources of high energy electromagnetic radiation are known as
Nebulae
Quasars
Meteors
Comets
The world's first artificial satellite Sputnik I was launched by Russia in
1985
1957
1959
1960
Why is nuclear fusion also known as thermonuclear reaction?
Fusion converts nuclear energy into heat
Fusion demands conditions of extremely high temperature to produce it
Fusion produces large amount of heat
Fusion reactions takes place in the sun
A nuclear reactor is said to have become 'critical' when
it stops due to malfunctioning
it starts emitting dangerous radioactive radiations
it is shut down to avoid explosion
it is ready to produce controlled energy
The earth satellite Aryabhatta was put in orbit by India on
October 20, 1978
November 14, 1978
January 26, 1979
April 19, 1975
An ammeter has
a high resistance
a very low resistance
no resistance at all
resistance of 400 � w
When a steel ball is placed on the surface of mercury, it does not sink because
of the surface tension of mercury
mercury is a semi-solid
of the high viscosity of mercury
the density of mercury is greater than that of steel
Commonly used safety fuse wire is made of
Tin
Lead
Nickel
An alloy of tin and lead
Which is the densest planet of the solar system?
Sun
Jupiter
Mercury
Earth
In a river, the currents are fastest where the river la
wide and shallow
narrow and shallow
wide and deep
narrow and deep
Diamond shines because of its
purity
hardness
high density
high refractive index and low critical angle
Among the following the most suitable material for the core of an electro-magnet is
steel
wood
soft iron
copper
When the disturbed electrons of an exited atom transfer back into lower energy levels they emit energy in the form of electromagnetic wave pulses called
neutrons
electrons
phonons
photons
The heating element often used in an electric iron is
copper
tungsten
mica
nichrome