The image of an object formed in a plane mirror
is real
is virtual
can be obtained on a screen
is slightly bigger than the object
Correct Answer :
B. is virtual
Related Questions
Galaxies emit
radio waves and X-rays
ultraviolet light waves
visible light waves
All the above
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 heating element often used in an electric iron is
copper
tungsten
mica
nichrome
When temperature decreases, resistance of metals to flow of electricity
increases
decreases
neither increases nor decreases
first increases then decreases
Some persons are not able to see distant objects clearly because the image of the object is focused in front of the retina. This defect is known as
short sight
long sight
astigmatism
presbyopia
The nuclear model of atom was first visualised by
Rutherford
Neils Bohr
Albert Einstein
JJ Thompson
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
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
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
A hydraulic brake in an automobile uses
a fluid to transmit the braking force
the force applied by the driver
hydrogen gas and not any liquid
a vacuum brake
Alpha particles are
electromagnetic radiations
helium nuclei
negatively charged particles
neutral particles
The velocity of sound in air increases with
the rise of temperature
rise of its frequency
decrease in humidity
fall of temperature
We see the sun before it actually rises on the horizon. This is due to
refraction
reflection
total internal reflection
parallax
The Space Application Centre for training in Satellite Communication Technology is located at
Bangalore
Mumbai
Ahmedabad
New Delhi
Which of the following wires of same dimensions offers least resistance to the ,flow of current?
copper
aluminium
silver
nichrome
The escape velocity of a satellite projected from the surface of the earth is independent of
the mass of earth
the mass of the satellite
the radius of the earth
gravitation of the earth
The source of electric energy in an artificial satellite is
mininuclear reactor
a dynamo
a thermopile
solar cells
In a river, the currents are fastest where the river la
wide and shallow
narrow and shallow
wide and deep
narrow and deep
The largest planet in the solar system is
Neptune
Uranus
Jupiter
Saturn
Lightning is produced when
similar charges of electricity rush towards each other and then get repelled
clouds strike against impurities in air and the friction burns up these impurities
strong opposite charges in different clouds break down the resistance offered by the intervening air
water vapour produces electricity in the clouds
When we sweat, we feel comfortable under a fan because
the air circulated by the fan is cool
the fan produces convection currents of air
the air circulated by the fan quickens the evaporation of the moisture on our skin
the air takes away the heat from our body
When an electric bulb breaks, there la 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
A bucket of water is hung from a spring balance. A piece of iron is suspended in the water without touching the sides or touching the bottom of the bucket. The reading of the spring balance
will increase
will decrease
does not change
varies with the increase of depth of the immersion of the iron piece
When ice just melts
there is no change in volume
there is no change in temperature
heat is given out
there is no change of state
When we tighten the string of a sitar or tanpura its pitch
remains the same
increases
decreases
None of the above
Solar radiation is preferred to other sources of energy because
it is practically inexhaustible
it is the cheapest form of energy
it does not cause pollution
All of the above
For detecting and, testing of small electric charges we use
an electrophorus
an electroscope
an electromagnet
an ammeter
The loudness of a sound is determined by
Frequency
Amplitude
Speed
Wavelength
When a light ray is reflected repeatedly by a set of parallel plane mirrors, the intensity of light ray diminishes alter a few reflections. This is because of
poor reflection from the mirrors
scattering of light from the mirrors
absorption of some light by the mirrors
absorption of light by the atmosphere
The largest reserve of radioactive element which can be used in a nuclear reactor has been found in India, The name of the element is
Thorium
Uranium
Plutonium
Radium