The light from the star nearest to the sun reaches the earth in
8 minutes
4.3 years
12 seconds
24 hours
Correct Answer :
B. 4.3 years
Related Questions
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
When the resistance of a circuit increases the current will
increase
decrease
remain the same
None of the above
The maximum displacement of the particle in a mechanical wave motion is known as
amplitude
vibration
frequency
phase
A proton is
the ionised hydrogen molecule
the nucleus of helium atom
the nucleus of hydrogen atom
the positive counterpart of electron
The rate of cooling of a hot body depends on
the nature of the radiating surface
area of the radiating surface
temperature difference between the body and the surroundings
All the above
The SI unit of electric current is
the ampere
the volt
the ohm
the coulomb
A hydrogen bomb is based on
nuclear fusion
nuclear fission
Both (a) and (b) above
Neither (a) nor (b)
An electric fan converts
electrical energy into heat energy
electrical energy into mechanical energy
mechanical energy into electrical energy
mechanical energy into heat energy
A man stands in a lift which accelerates upwards. The resultant reaction force on the floor of the lift is
greater than the weight of the man
less than the weight of the man
same as the weight of the man
zero
Expansion of a rod when heated
is proportional to its original length
is proportional to the increase of temperature
is inversely proportional to its original length
Both (a) and (b) above
To concentrate light on the defective teeth, the dentists use
convex mirrors
concave mirrors
convex lens
concave lens
Electromagnets are used in
the telephone ear piece
the telegraph
the electric bell
All the above
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
A bar magnet tied in the middle with a thread is suspended at the South Pole of the earth. The magnet will be in
a horizontal position
a nearly vertical position with its South Pole downwards
a nearly vertical position with its North Pole downwards
a slanting position
Alternating Current (AC) is more advantageous than direct current because
it can be transmitted easily and efficiently
Alternating Current (AC) loses the least amount of energy when transmitted at high voltages
Alternating Current (AC) voltage can be easily increased or decreased
all the above
When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of
surface tension
capillarity
viscosity
diffusion
The planet that has got a well-developed set of rings is
Venus
Saturn
Mercury
Earth
To produce beats it is necessary to have two waves
travelling in opposite direction
of slightly different frequencies
of equal wavelength
of equal amplitude
Where does the centre of gravity of a rubber ring lie?
on the outer surface
in the inner surface
at the centre of the ring
None of the above
When a ship floats on water, the weight or water displaced is
an indeterminate quantity
equal to the weight of the ship
greater than the weight of the ship
less than the weight of the ship
A tube light works on the principle of
chemical, heating and magnetic effects of electricity
discharge of electricity through gases
the action of ultraviolet radiation on certain fluorescent materials
Both (b) and (c) above
We cannot see and without the aid of a telescope
Neptune and Pluto
Jupiter and Saturn
Venus and Mars
Venus and Saturn
The planet that spins Caster than any other planet is
Saturn
Jupiter
Earth
Mercury
Water has maximum density at
0° C
-15° C
4° C
15° C
We see the sun before it actually rises on the horizon. This is due to
refraction
reflection
total internal reflection
parallax
A lactometer la used to
find out the specific gravity of liquids
measure the volumes of liquids
test the purity of milk
determine the strength of acid in car batteries
Pyrometers are instruments used
for measuring the velocity of wind
in the manufacture of fireworks
in finding the coefficient of apparent expansion of a liquid
for measuring high temperatures
The star nearest to the sun is
Proxima Centauri
Sirius
Aldebaran
Vega
An integrated circuit is 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
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