Sound waves In 'air travel faster if
frequency is higher
wavelength is smaller
pitch is smaller
air is warmer
Correct Answer :
D. air is warmer
Related Questions
When an incident beam of light strikes the surface of a glass slab normally, the refracted beam
goes straight through without bending
gets deviated away from the normal
gets bent towards the normal
gets reflected
A thermostat is a device used
for automatically maintaining a steady temperature
for measuring electricity
to reduce the voltage of electricity
for producing heat
To get 5 images of a single object one should have two plane mirrors inclined at an angle of
72°
60°
36°
90°
A device used to measure heights above sea level is known as
altimeter
anemometer
dilatometer
potentiometer
A pair of stars that revolve round each other is
a neutron star
a binary star
a dwarf star
a polar star
The device used to record the sound is
a microphone
a headphone
a phonograph
an amplifier
The body of an electrical appliance is earthed in order that
electricity may not leak
there may be smooth flow of electricity
a short circuit may be prevented
current may pass to the earth in case of a short circuit without doing any harm to the person
Sound travels fastest in
air
water
iron
vacuum
In the visible spectrum which colour has the shortest wavelength?
Red
Blue
Yellow
Violet
A hydrogen bomb is based on
nuclear fusion
nuclear fission
Both (a) and (b) above
Neither (a) nor (b)
The resistance of a wire depends on
the material of the wire
the length of the wire
the cross section of the wire
All the above
Heat transfer
cools the body that transfers it
heats the body that absorbs the heat
may change the physical state of the substance
All the above
The instrument used to determine the RD (Relative Density) of a liquid by the principle of floatation is
Hygrometer
Hypsometer
Hydrometer
Densimeter
In hot climatic conditions, the buildings are painted white because
white paint is economical
it does not fade off
it does not crack with higher temperature
white coating is a bad conductor of heat and reflects heat rays that fall on it, thus keeping the inside cool
The star nearest to the sun is
Proxima Centauri
Sirius
Aldebaran
Vega
A balloon ruled with hydrogen will
continue going upwards uninterrupted
reach a particular height and remain floating
burst after reaching some height
reach a particular height and start coming down
When white light passes through a glass prism we get a spectrum on the other side of the prism. In the emergent beam the ray which is deviated least is
the violet ray
the red ray
the green ray
the blue ray
Out of the following, name the fluorescent substance.
quinine sulphate solution
paraffin oil
fluorescein solutions
All the above
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
A small bubble of air deep down in a lake rises up to the top of the lake. The volume of the bubble on coming up will
increase
decrease
will not change
first increase and then decrease
X-rays are
deflected by electric field
deflected by magnetic field
slightly deflected by electric field and magnetic field
not deflected by electric and magnetic fields
The first Indian Satellite launched from a Russian Cosmodrome on April 16, 1975 was named
Bhaskara
Insat I-A
Aryabhatta
SLV-l
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
Why is it cool near an open pond on a hot summer day?
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
The mass number and the atomic number of an element are X and Y respectively. The number oC neutrons in the atom of that element is
X
Y
X + Y
X Y
Choose the scalar quantity from the following physical quantities
force
velocity
acceleration
speed
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
The aneroid barometer uses
mercury
distilled water
alcohol
does not use any liquid
When a satellite is In a geostationary orbit the force keeping it in orbit Is
zero
the centrifugal force
reaction due to steady burning of fuel
the gravitational pull on the body by the earth is the weight of the body which provides the centripetal force
The asteroids belt lies between the orbits of
Earth and Mars
Venus and Earth
Mars and Jupiter
Moon and Mars