In a freezer ice cubes will be formed more quickly in trays made of
rubber
plastic
aluminium
wood
Correct Answer :
C. aluminium
Related Questions
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 Indian Space Research Organisation (ISRO) is located at
Thumba
Bangalore
Ahmedabad
New Delhi
The overhead wires supported by high towers in the grid system carry
alternating current of very high frequency
alternating current of very high voltage
a very large direct current
a high voltage direct current
Under similar conditions of temperature and pressure, the velocity of sound is maximum in
helium
argon
hydrogen
oxygen
A thermostat is a device used
for automatically maintaining a steady temperature
for measuring electricity
to reduce the voltage of electricity
for producing heat
Resistance is measured in
Volts
Amperes
ohms
coulombs
Alpha particles are
electromagnetic radiations
helium nuclei
negatively charged particles
neutral particles
Which of the following is not electromagnetic waves?
heat waves
sound waves
radio waves
light waves
The brightest star visible to the naked eye is
Sirius
Vega
Rigel
Proxima Centauri
It is more difficult to walk on ice than on a concrete road because
there is very little friction between the ice and feet pressing it
ice is soft when compared to concrete
there is more friction between the ice and feet
None of the above
Cosmic rays contain
protons and electrons
alpha particles
gamma rays
All the above
The hydraulic jack to lift heavy vehicles in automobile service stations is one of the applications of
Pascal's law
Principle of Archimedes
Boyle's law
Hooke's law
Electron-volt is a unit of
power
velocity
energy widely used in nuclear physics
number of electrons
To concentrate light on the defective teeth, the dentists use
convex mirrors
concave mirrors
convex lens
concave lens
Tea pots are highly polished
so that they may reflect thermal radiation from outside and minimise such radiation from them
so that they may absorb all radiation from outside
to make them attractive to look at
because they take high polish
A person cups his hand around the mouth when shouting. Why?
Sound energy from his mouth is then directed in one direction
The cupped hand acts as a cardboard tube of short length
The pitch of sound increases
Both (a) and (b)
The filament lamp is an example for
fluorescence
incandescence
both (a) and (b)
None of these
The inside of both the walls of a thermos flask is silvered i.e., on the vacuum side in order to reduce heat loss by
convection
radiation
conduction
All the three
Dioptre is the unit of power of
convex mirrors
concave mirrors
concave lenses
lenses irrespective of types
A radio set that uses valves does not start operating immediately when it is switched on whereas a set containing only tranaistors operates immediately. The reason for this is that
the valve filaments have low resistance
valve-radio sets work at a higher voltage
transistor set has a low resistance
filaments of the valves cake time to beat up and function
Radio waves sent out by radio stations are reflected by
troposphere
stratosphere
mesosphere
ionosphere
Photocells are used
in burglar alarms
in automotive devices for light switches
television cameras
All the above
A radio set that uses valves does not start operating immediately when it is switched on whereas a set containing only tranaistors operates immediately. The reason for this is that
the valve filaments have low resistance
valve-radio sets work at a higher voltage
transistor set has a low resistance
filaments of the valves cake time to beat up and function
The instrument used to determine the RD (Relative Density) of a liquid by the principle of floatation is
Hygrometer
Hypsometer
Hydrometer
Densimeter
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
The focal length or lens or the eye is under the control or the
iris
pupil
ciliary body
cornea
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
A man Jumping out of a moving train is thrown
forward
backward
sideways
None of the above
One can be recognised by his voice alone due to the factor of
quality
amplitude
pitch
loudness
Diamond shines because of its
purity
hardness
high density
high refractive index and low critical angle