Which of the following rays has the highest penetrative power?
�± -rays
�² -rays
�³ -rays
X-rays
Correct Answer :
C. �³ -rays
Related Questions
Gamma radiations are used for
sterilising food stuff
controlling pests
cancer therapy
All of these
In an electrical circuit, a fuse is connected
in the live wire
in the neutral wire
in the earth wire
anywhere
Choose the correct answer
Microphone converts sound energy into electrical energy.
Electric fan converts electrical energy into mechanical energy.
Battery converts chemical energy into electrical energy.
All the above
The radius of curvature of a spherical mirror is
equal to half its focal length
equal to its focal length
twice its focal length
not related to its focal length
In compact porous soil, the rising of the water is due to
capillarity
cohesion
adhesion
viscosity
The completely dark portion of a shadow of an object is known as
umbra
penumbra
image
black portion of light
The air inside an electric, bulb is removed to prevent
oxidation of the tungsten filament
bursting of the bulb
loss of light due to absorption
keeping the weight of the bulb less
In a concert hall reverberation is controlled by
reduction of seating capacity in the hall
increase of sound intensity in the hall
lining the walls, with leather panels put on over a layer of sound absorbent glass fibre
by opening the doors and windows of concert hall
Chronometer la an instrument to measure
heat
electric potential
time
distance between two points
Water kept in an earthen pot is less cool on rainy days than in summer because during the rainy days
the pores in the pot are closed
rain water stops oozing out from the pores
the water that oozes out does not evaporate quickly because of the large percentage of moisture in the air
surface of the pot becomes damp
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
A piece of cork la embedded inside an ice block which floats in water. What will happen to the level of water when all ice melts?
It will go down
It will come up
It will remain at the same level
First it will go down and it will come up
The number of electrons in the outer orbits of a nucleus gives
the mass number
atomic number
atomic weight
absolute number
The velocity of sound in air increases with
the rise of temperature
rise of its frequency
decrease in humidity
fall of temperature
When ice melts, Its volume
decreases
increases
remains the same until all the ice has melted and then increases
remains the same
In a refrigerator cooling is produced by
the ice that deposits on the freezer
the evaporation of a volatile liquid
None of the above
Both (a) and (b)
The temperature of a large bucket-full of hot water (a few degrees below boiling point) is lower than a beaker full of boiling water. But
the hot water contains a much larger quantity of internal energy than the boiling water
the boiling water contains more quantity of internal energy than the warm water
both of them have got the same amount of internal energy.
nothing can be said definitely with the data given
The aneroid barometer uses
mercury
distilled water
alcohol
does not use any liquid
Thick brick walls are used in the construction or a cold storage because bricks
are good conductors of heat
are cheaper
are easily obtained
are bad conductors of heat
When water is cooled from 4�C to 2�C its density
increases
decreases
remains the same
first increases then decreases
The cell that can be recharged, after it has run down, by passing a direct current through it from a source of current is
Voltaic cell
Leclanche cell
Dry cell
An accumulator
The instrument used to measure the strength of electric current at a point is
Ammeter
Altimeter
Adrinometer
Anemometer
The rate of cooling of a hot body depends on
the nature of the radiating surface
area of the radiating surface
temperature difference between the body and the surroundings
All the above
Which of the following sets of elementary particles have nearly equal masses?
Neutron and Proton
Electron and Proton
Neutron and Electron
Proton, Neutron and Electron
An astronomical unit of distance is
a kilometre
light year
the average distance from the earth to the sun
None of the above
Mica is used in an electric iron because it is a
good conductor of heat
good conductor of electricity
bad conductor of electricity
Both (a) and (b) above
When light travels from one medium to another there is a change in its
velocity
wavelength
frequency
Both (a) and (b) above
If an empty cylinder Is half ruled with a liquid, Its centre of gravity is
shifted upwards
shifted downwards
shifted neither upward nor downward
shifted upward or downward depending on the density of the liquid
Two tumblers stuck together can be separated by
pouring ice cold water into the inner tumbler
pouring ice cold water on the outer tumbler
pouring hot water into the inner tumbler
dipping both the tumblers in hot water
The scientist who first sent electromagnetic waves to distant places was
James Clerk Maxwell
Heinrich Hertz
Thomas Alva Edison
Baird