A convex mirror always produces
an erect, virtual image of diminished size
an erect, real image of diminished size
an erect, real image of double size
a virtual image of double size
Correct Answer :
A. an erect, virtual image of diminished size
Related Questions
The leader of the team who succeeded in constructing the first nuclear reactor (an atomic pile) in the world was
Albert Einstein
Enrico Fermi
HJ Bhabha
Sir Isaac Newton
Among the following the most suitable material for the core of an electro-magnet is
steel
wood
soft iron
copper
The heating element often used in an electric iron is
copper
tungsten
mica
nichrome
The phenomenon of radioactivity was discovered by
Rutherford
Bohr
Henri Bacquerel
Marie Curie
The inability of a body to change its state of rest or uniform motion along a straight line is called its
momentum
velocity
acceleration
inertia
The stem of a vibrating tuning fork is pressed against a sound box. Then
the loudness of the sound increases
the loudness remains the same
the loudness decreases
the sound suddenly stops
In a vacuum the following three articles are dropped at the same time and from the lame height. Which will reach the ground quicker?
a stone
a piece of wood
a feather
all will reach the ground at the same time
Which of the following is not electromagnetic waves?
heat waves
sound waves
radio waves
light waves
The attraction of unlike molecules at the common surface is known as
adhesion
cohesion
surface tension
capillarity
SONAR (Sound Navigation Ranging) is
used by warships and military aircraft to locate enemy submarines
used by ships to determine the depth of water beneath them
a detective device that uses sound to locate under - water objects
All the above
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
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 aneroid barometer uses
mercury
distilled water
alcohol
does not use any liquid
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
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 transistor was invented by
Marconi
Baird
John Bardeen, Walter H. Brattain and William Shockley
Edison
In a river, the currents are fastest where the river la
wide and shallow
narrow and shallow
wide and deep
narrow and deep
An integrated circuit la more advantageous than a conventional circuit because
they make the electric equipment more reliable and easier for servicing
a faulty part of a conventional circuit may be difficult to locate and repair
if a part of the integrated circuit fails the entire circuit is simply replaced
All the above
The electroplating of a metallic article
protects the article from atmospheric corrosion
gives it a more attractive appearance
Both (a) and (b) above
None of 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
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
The velocity of sound in a medium is
directly proportional to its pressure
inversely proportional to the square root of its pressure
directly proportional to the square root of its pressure
independent of its pressure
Separating particles from a suspension is effected by
centrifugal force
frictional force
gravitational force
distillation
The colour of a star is an indication of its
distance from the earth
age
temperature
size
An ammeter has
a high resistance
a very low resistance
no resistance at all
resistance of 400 ? w
On the Kelvin scale, the melting point of ice is
0 K
273 K
373 K
100 K
Halley's comet appears in the heavens once in
40 years
50 years
76 years
80 years
Hydrophone is an instrument used
for measuring relative density of liquids
by ships to pass on messages
for determining the depth of ocean bottoms etc.
by deaf people to aid hearing
It is easier to climb down a staircase than climb up because in climbing down
work is done against gravity
the steepness of the staircase isn't felt
gravity assists
there is no friction between the legs and steps
An astronomical unit of distance is
a kilometre
light year
the average distance from the earth to the sun
None of the above