direct sun's rays
radiation from earth's surface
radiogenic heat (resulting from radioactive decay)
cosmic rays coming from space
B. radiation from earth's surface
to absorb unwanted neutrons
to slow down the fast neutrons to secure more effective hits on other nuclei
to decrease the number of fissile nuclei
to increase the number of fissile nuclei
increases as the square root of the absolute temperature
decreases with temperature
is independent of temperature
None of these
replace the fuse by a thin wire
replace the fuse by a thick copper wire
replace the fuse by a fuse wire of proper rating
replace the fuse by nichrome wire
neutrons
electrons
phonons
photons
a reflecting elliptical portion
a reflecting spherical surface
a parabolic reflecting surface
a flat reflecting surface
is proportional to that of the Celsius thermometer
is always greater than that of the Celsius thermometer
is always less than that of the Celsius thermometer
may be greater than or less than or equal to that of the Celsius thermometer
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
air
water
iron
vacuum
convex mirrors
concave mirrors
concave lenses
lenses irrespective of types
Dalton
Rutherford
Einstein
Planck
heat waves
sound waves
radio waves
light waves
velocity
wavelength
frequency
Both (a) and (b) above
Jupiter
Mars
Mercury
Saturn
work is done against gravity
the steepness of the staircase isn't felt
gravity assists
there is no friction between the legs and steps
1
infinite
0
4
U-234
U-235
U-238
Both (b) and (c)
an electrophorus
an electroscope
an electromagnet
an ammeter
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
the heat content of A is greater than that of B
the temperature of A is greater than that of B
the specific heat of A is greater than that of B
the specific heat of B is greater than that of A
Daniell cell
Leclanche cell
Dry cell
All the above
330 m
33 m
16.5 m
165 m
40 years
50 years
76 years
80 years
the reflection of sound waves
the refraction of sound waves
the interference of sound waves
reverberation of sound waves
attract each other
repel each other
neither attract nor repel
attract or repel depending upon the conditions
Albert Einstein
Enrico Fermi
HJ Bhabha
Sir Isaac Newton
sterilising food stuff
controlling pests
cancer therapy
All of these
it is nearest to the moon
it is nearest to the sun
it is nearest to Pluto
it is farthest from the sun
brown for earth, yellow for live, light blue for neutral
green for earth, yellow for live, brown for neutral
yellow for earth, green for live, brown for neutral
brown or red for live, light blue or black for neutral and green or yellow for earth
the electrical attraction between the negatively charged electron and the positively charged porton
the high speed of the electron
the low speed of the electron
gravity
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