A light year means
a unit of time
a unit of length
a year of no consequence
illumination throughout the year
Correct Answer :
B. a unit of length
Related Questions
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
A man stands on the pan of a balance holding a fish in his right hand and bucket of water in his left hand. If he transfers the fish into the bucket, the total weight on the pan
increases
decreases
remains the same
first increases and then decreases
The mode of travel of heat energy from the sun across the empty space beyond the earth's atmosphere is known as
conduction
convection
radiation
absorption
If a body is taken from the earth to the moon
both its mass and weight will be different
its mass will be different but the weight will remain the same
its mass and weight will both remain unchanged
its mass will remain the same but weight will be different
The earth satellite Aryabhatta was put in orbit by India on
October 20, 1978
November 14, 1978
January 26, 1979
April 19, 1975
Holography is the technique of
taking photos of various objects
recording and reproducing three dimensional images
tracing out planets and stars in the sky
transmitting light waves
Water has maximum density at
0° C
-15° C
4° C
15° C
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
When a whistling engine approaches a person standing on the platform, the frequency or the note
appears to increase
appears to decrease
does not change at all
first increases then decreases
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
The following are the atmospheric zones above the surface of the earth:
A) Troposphere
B) Ionosphere
C) Stratosphere
D) Exosphere
Select the correct sequence from the earth's surface on the basis of the codes given below:
ACBD
ABCD
CABD
BACD
The transistor was invented by
Marconi
Baird
John Bardeen, Walter H. Brattain and William Shockley
Edison
When a swing is drawn to a side Its potential energy In relation to the earth
increases
decreases
remains the same
is constant
Increase in pressure
increases the melting point of ice
decreases the melting point of ice
has no effect on the melting point of ice
increases the volume of the ice
You want a supply of a small but constant current. Which of the following cells will you prefer?
Daniell cell
Leclanche cell
Dry cell
All the above
In the electrical circuit of a house the fuse acts as
a thermopile
a load
a step down device
a safety device
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
The scientist who first sent electromagnetic waves to distant places was
James Clerk Maxwell
Heinrich Hertz
Thomas Alva Edison
Baird
The maximum range of most TV signals is from 121 to 240 km only because
the curvature of earth limits the range of reception
the signals are weak
the signals are absorbed by air
the antennae are not powerful enough
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 radius of an atom is approximately
10-10 cm
10-12 cm
10-13 cm
10-16 cm
The loudness of a sound is determined by
Frequency
Amplitude
Speed
Wavelength
If an object is placed between two parallel plane mirrors, the number of images formed will be
1
infinite
0
4
The minimum velocity required by a satellite to escape earth's gravitational pull is
18 km/s
11.2 km /s
21 km/s
35 km/s
If a man wants to hear clearly the echo of a sound produced by him from a hill, the hill should be away from him by a minimum distance of
330 m
33 m
16.5 m
165 m
Antiparticle of electron is
proton
antiproton
positron
neutron
Before the invention of geostationary satellites, television stations could not transmit their programmes to far off places because
these signals are electromagnetic in nature
these are not electromagnetic in nature
their wavelength is very large
they are not reflected by the ionosphere but pass through it
A body has fallen from a height. Just before touching the pound it has
lost all its potential energy and gained an equivalent amount of kinetic energy
gained potential energy and lost kinetic energy
gained kinetic energy as well as potential energy
lost kinetic energy as well as potential energy
A ruse wire is characterised by
high resistance and high melting point
high resistance and low melting point
low resistance and high melting point
low resistance and low melting point
A person cups his hand around the mouth when shouting. Why?
Sound energy from his mouth is then directed in one direction
The cupped hand acts as a cardboard tube of short length
The pitch of sound increases
Both (a) and (b)