Railway tracks are banked on curves so that
the necessary centrifugal force may be obtained from the horizontal component of the weight of the train
the frictional force between the track and the wheels is avoided
the necessary centripetal force may be derived from the horizontal component of the weight of the train
None of these
Correct Answer :
C. the necessary centripetal force may be derived from the horizontal component of the weight of the train
Related Questions
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
When a bottle of perfume la opened in one corner of a room the smell spreads soon throughout the room. This is an example of
surface tension
capillarity
viscosity
diffusion
Lightning is produced when
similar charges of electricity rush towards each other and then get repelled
clouds strike against impurities in air and the friction burns up these impurities
strong opposite charges in different clouds break down the resistance offered by the intervening air
water vapour produces electricity in the clouds
The phenomenon of radioactivity was discovered by
Rutherford
Bohr
Henri Bacquerel
Marie Curie
The Space Application Centre for training in Satellite Communication Technology is located at
Bangalore
Mumbai
Ahmedabad
New Delhi
Hot water is poured simultaneously in four metallic tumblers painted outside with different paints. After some time the water will be found to have cooled most in the tumbler painted.
rough white
rough black
shining white
shining black
A man Jumping out of a moving train is thrown
forward
backward
sideways
None of the above
Which force is used when milk is churned to separate cream?
cohesive
centrifugal
frictional
gravitational
How is it that Pluto is not always the farthest planet of the solar system?
Each planet becomes the farthest planet in its turn. Now it is the turn of Piuto
The Sun is now in the zodiac in which it is nearest to outer planets
The eccentricity of Piuto's orbit being substantial, this orbit cuts the orbit of Neptune
Piuto belongs to other solar system
Which is the densest planet of the solar system?
Sun
Jupiter
Mercury
Earth
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
Skating on ice is possible because
the surface of ice is smooth
ice is cold
the pressure on the ice due to skate melts the ice by lowering its melting point forming a thin film of water
the pressure on the ice due to skate raises its melting point
The mode of travel of heat energy from the sun across the empty space beyond the earth's atmosphere is known as
conduction
convection
radiation
absorption
The rocket engine is motivated by jet propulsion which uses the famous
Kepler's Laws
Newtonian Third Law of Motion
Bernoulli's Principle
Law of Relativity
The best estimates of the age of the earth comes from the studies of
angle of inclination of the earth
changes in radio-active minerals in it
period taken by Sun's light to reach the earth
artificial satellites revolving round the earth
The heat produced in a conductor due to the passage of a current through it is proportional to
the square of the current
the resistance of the conductor
the time for which the current flows
All the above
Air escaping rapidly from a narrow orifice in an inflated tyre feels cool because
the speed with which it escapes cools it down
of the higher temperature of the surroundings
of sudden expansion causing loss of internal energy
there is no real fall in temperature
In hot climatic conditions, the buildings are painted white because
white paint is economical
it does not fade off
it does not crack with higher temperature
white coating is a bad conductor of heat and reflects heat rays that fall on it, thus keeping the inside cool
A man stands in a lift which accelerates upwards. The resultant reaction force on the floor of the lift is
greater than the weight of the man
less than the weight of the man
same as the weight of the man
zero
The nuclear model of atom was first visualised by
Rutherford
Neils Bohr
Albert Einstein
JJ Thompson
The solar wind is composed of
outward stream of protons and electrons on the surface of the sun during solar flares and sun-spot activity
plasma
ionized gas
All of these
Which metal is used in storage batteries?
Copper
Lead
Tin
Iron
Drinks kept in a vacuum flask remain hot or cold as the case may be for a long time because
both walls are silvered on the vacuum side
there is vacuum between the double walls
the cork is a poor conductor of heat
of all the above
Heat transfer
cools the body that transfers it
heats the body that absorbs the heat
may change the physical state of the substance
All the above
Increase in pressure
increases the melting point of ice
decreases the melting point of ice
has no effect on the melting point of ice
increases the volume of the ice
Moon has no atmosphere because
it has no population
it is quite far off
its surface is full of rocks
its gravity is not sufficient for any atmosphere to hold on to it
When ice just melts
there is no change in volume
there is no change in temperature
heat is given out
there is no change of state
Photocells are used
in burglar alarms
in automotive devices for light switches
television cameras
All the above
An electric fan converts
electrical energy into heat energy
electrical energy into mechanical energy
mechanical energy into electrical energy
mechanical energy into heat energy
Sound waves In 'air travel faster if
frequency is higher
wavelength is smaller
pitch is smaller
air is warmer