A boy sitting in a train moving with a uniform velocity drops a coin outside. A man standing outside the train will find the trajectory of the coin to be
a parabola
a horizontal straight line
a vertical straight line
a circle
Correct Answer :
A. a parabola
Related Questions
A bucket of water is hung from a spring balance. A piece of iron is suspended in the water without touching the sides or touching the bottom of the bucket. The reading of the spring balance
will increase
will decrease
does not change
varies with the increase of depth of the immersion of the iron piece
In which of the following will a piece of iron weigh most?
in air
in an atmosphere of oxygen
in an atmosphere of CO2
in vacuum
If the speed of the rotation of the earth increases the weight of a body
will increase
will decrease
will have no change
will either increase or decrease
Among the following the most suitable material for the core of an electro-magnet is
steel
wood
soft iron
copper
Pieces of camphor placed on water move about rapidly. This is because of
diffusion
viscosity
surface tension
capillarity
The Cact that the compass needle does not point true north was observed first by
Sir Isaac Newton
Columbus
Archimedes
Thomas Alva Edison
When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of
surface tension
capillarity
viscosity
diffusion
The largest reserve of radioactive element which can be used in a nuclear reactor has been found in India, The name of the element is
Thorium
Uranium
Plutonium
Radium
The transistor was invented by
Marconi
Baird
John Bardeen, Walter H. Brattain and William Shockley
Edison
Nichrome is used in electric heaters and irons because
it resists oxidation when red hot
its melting point is high
it has got 60 times the resistance of copper
All the above
Sound waves
are electromagnetic waves
can easily pass through vacuum
are always transverse waves
require a material medium for propagation
A stone floor feels cold to the bare feet but a carpet on the same floor feels warm. This is because
the floor and carpet are at different temperatures
the stone conveys the heat away from the feet more rapidly than the carpet
the carpet is a better conductor of heat than the stone
the human body maintains a constant temperature
A cyclist leans inwards when he is negotiating a curve 10 that
he may increase his speed
his weight may be reduced
necessary centripetal force may be available from the horizontal component of the normal reaction due to the track to maintain the curved motion
no frictional force may be produced between the wheels and the axle
A boy sitting in a train moving with a uniform velocity drops a coin outside. A man standing outside the train will find the trajectory of the coin to be
a parabola
a horizontal straight line
a vertical straight line
a circle
X-rays are used
in hospital in the treatment of malignant growth
to reveal hidden flaws in metal castings and welded joints
to detect alterations made in works of art
All the above
Less dew is formed on cloudy nights because
there is no moisture in the atmosphere
clouds absorb the falling dew
objects emit radiant energy very fast on such nights
objects lose less radiant energy
A star contains
about 75% of hydrogen
22% helium
traces of most other elements including oxygen, neon, carbon and nitrogen
All the above
The brightest star visible to the naked eye is
Sirius
Vega
Rigel
Proxima Centauri
A proton is
a quantum of light energy
a quantum of matter
a positively charged atomic particle
another name for positron
A ship sailing from a river to the sea
sinks less in the sea
sinks more in the sea
neither sinks more nor less in the sea
sinking more or less depends on sea
A piece of ice is Boating In water kept in a beaker. When all the ice melts the level of water will
first rise and then fall
fall
remain the same
rise
The colour of the light which travels through glass with minimum speed is
red
violet
green
yellow
A body has fallen from a height. Just before touching the pound it has
lost all its potential energy and gained an equivalent amount of kinetic energy
gained potential energy and lost kinetic energy
gained kinetic energy as well as potential energy
lost kinetic energy as well as potential energy
The force of attraction or repulsion between two charged bodies is directly proportional to the product of the charges and inversely proportional to the square of distance between them. This was propounded by
Coulomb
Gilbert
Volta
Rutherford
The planet that is known as earth's twin is
Mercury
Venus
Moon
Mars
Atoms which have the same atomic number but different mass numbers are called
isobars
isomers
isotones
isotopes
Which of the following pairs is not correct?
Television - Baird
Transistor ~ Shockley
Thermometer - Celsius
Barometer Torricelli
In the nucleus of an atom, the uncharged particle is
proton
neutron
electron
positron
In a longitudinal wave, the direction of propagation of the wave is
the same as the direction of the vibrations of the vibrating body
at right angles to the direction of the vibrations of the vibrating body
Both (a) and (b) above
None of the above
The orbit of Venus lies between those of
Mercury and Earth
Earth and Mars
Mars and Saturn
Mars and Jupiter