The audible range of a normal human ear is frequencies ranging from
10000 to 20000 Hz
50 to 15000 Hz
20 to 20000 Hz
15 to 50000 Hz
Correct Answer :
C. 20 to 20000 Hz
Related Questions
We always see only one side of the moon because
the sun comes in between the earth and moon
the moon is stationary
the time taken by the moon to rotate on its axis is the same as the time taken by it to revolve round the earth
moon revolves round the sun
A nuclear reactor is said to have become 'critical' when
it stops due to malfunctioning
it starts emitting dangerous radioactive radiations
it is shut down to avoid explosion
it is ready to produce controlled energy
The planet that spins Caster than any other planet is
Saturn
Jupiter
Earth
Mercury
The difference between planets and stars is
planets do not have light of their own whereas stars shine by their own light
planets do not twinkle like stars
planets are much smaller than stars
All the above
In the visible spectrum which colour has the shortest wavelength?
Red
Blue
Yellow
Violet
When an electric bulb breaks, there is an explosive sound. That is due to
the chemical reaction between the gases inside the bulb
the compressed gases inside rushing out suddenly
the air outside rushing in to fill the vacuum inside the bulb
None of the above
At what temperature do the Fahrenheit and Celsius scales give the same reading?
212°
32°
-40°
0°
Pieces of camphor placed on water move about rapidly. This is because of
diffusion
viscosity
surface tension
capillarity
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
At temperature near OK, (zero kelvin) metals such as lead and tin become
insulators
semiconductors
superconductors
condenser
Why is nuclear fusion also known as thermonuclear reaction?
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
In an oil lamp, holes are provided below the chimney so that
necessary oxygen for burning of oil may be provided
the convection current of air may be maintained to keep the lamp burning
the brightness of the lamp may be increased
All the above
In the case of bodies falling under gravity which of the following remains constant at a given place?
kinetic energy
potential energy
acceleration
All the above
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
A thermostat is a device used
for automatically maintaining a steady temperature
for measuring electricity
to reduce the voltage of electricity
for producing heat
The velocity of sound in air increases with
the rise of temperature
rise of its frequency
decrease in humidity
fall of temperature
Which of the following wires of same dimensions offers least resistance to the ,flow of current?
copper
aluminium
silver
nichrome
Rays from the headlight of a motor car are rendered parallel by suitably using
a convex mirror behind it
a concave lens behind it
a concave mirror in front of it
a concave mirror behind it
Cosmic rays contain
protons and electrons
alpha particles
gamma rays
All the above
The temperature, surface features, length of days and nights of a planet depend on
its atmosphere
its distance from the sun
its rotation
All the above
In a refrigerator, the refrigerant is
Nitrogen
Oxygen
Chlorine
Freon
Hot water is poured simultaneously in four metallic tumblers painted outside with different paints. After some time the water will be found to have cooled most in the tumbler painted.
rough white
rough black
shining white
shining black
Nuclear fission process means
absorption of a neutron by a nucleus
breakup of the nucleus of a heavy atom into two nearly equal halves emitting two or three neutrons and releasing large amounts of nuclear energy in the process
the scattering of neutrons
formation of heavier nucleus
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
A bullet is fired at a certain angle with the horizontal. Its path will be
elliptical
a straight line
a parabola
a vertical line
The theory that the earth constituted the centre of the universe around which the sun and the planets revolved was propounded by
Copernicus
Ptolemy
Newton
Kepler
If a bar magnet is broken into two pieces
both pieces will lose their magnetism
one piece will have North Pole on both ends and the other South Pole on its both ends
each will remain a magnet with North Pole at one end and South Pole at the other
the longer piece will behave as a bar magnet while the smaller will have no magnetism at all
When the velocity of a body is halved
its momentum is halved
its kinetic energy is halved
its acceleration is halved
its potential energy is halved
The number of electrons in the outer orbits of a nucleus gives
the mass number
atomic number
atomic weight
absolute number
Diamond shines because of its
purity
hardness
high density
high refractive index and low critical angle