able to refract the sound
good absorbers of sound
good reflectors of sound
All the above
B. good absorbers of sound
colours of the rainbow
colours in the spectrum of white light
colours which cannot be produced by mixing other colours
colours found in nature
look like falling stars
are really pieces of rock or metal
burn up as they shoot through the air
All the above
proton
neutron
electron
positron
turbulence caused by the wind
buoyancy of air
unequal pressures acting on it
sudden change in the direction of the wind
it is practically inexhaustible
it is the cheapest form of energy
it does not cause pollution
All of the above
a reflecting elliptical portion
a reflecting spherical surface
a parabolic reflecting surface
a flat reflecting surface
the atoms and molecules lose their identity
nucleus is split into fragments
the nuclear reaction between two light atomic nuclei results in the formation of a heavier nucleus with release of a large quantity of nuclear energy in the process
absorption of neutron by a nucleus
equal to its focal length
equal to its radius of curvature
equal to the reciprocal of its focal length (in metres)
equal to twice its focal length
light travels very much faster than sound
sound travels faster than light
lightning occurs nearer than thunder
both travel at the same speed
radio waves and X-rays
ultraviolet light waves
visible light waves
All the above
Rutherford
Bohr
Henri Bacquerel
Marie Curie
mininuclear reactor
a dynamo
a thermopile
solar cells
light comes through circular gaps between the leaves
the leaves are circular
the rays bend to form circular spots
the gaps between the leaves act as pin holes
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
umbra
penumbra
image
black portion of light
the nature of the liquid
area of the exposed surface of the liquid
temperature of air and of the liquid
All the above
these signals are electromagnetic in nature
these are not electromagnetic in nature
their wavelength is very large
they are not reflected by the ionosphere but pass through it
their heat contents
their masses
their temperatures
whether they are in solid, liquid or gaseous state
the mass number
atomic number
atomic weight
absolute number
coulomb
ampere
volt
watt
velocity
wavelength
frequency
Both (a) and (b) above
power
velocity
energy widely used in nuclear physics
number of electrons
mercury thermometers
alcohol thermometers
platinum resistance thermometers
thermoelectric thermometers
the ball will travel towards the centre of the circle and fall down
it will continue to travel along a tangent to the circle at the point the ball was at the time of snapping and finally fall down
it will fall down at the same place where the string breaks
None of these
is more than at sea level
is equal to that sea level
is less than at sea level
depends on the surrounding temperature
Evaporation at the surface causes cooling
The heat obsorbed at the surface is passed on to the bottom
Because of impurity in the water
Because of convection currents set up inside water
a microscope
a telescope
a stereoscope
a spectroscope
Tin
Lead
Nickel
An alloy of tin and lead
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
Voltaic cell
Leclanche cell
Dry cell
An accumulator