Two stars of different galaxies in the universe move away from each other. Sometimes, two stars of different galaxies may move towards each other in course of time.Which of the following inferences can be drawn from the observation?
Stars repel each other.
Stars attract each other.
Galaxies are expanding.
Galaxies are contracting.
The universe is formed by the expansion of primordial condition. This primordial condition expanded because of.
magnetic field
nuclear reaction
violent explosion
thermal expansion
A njattuvela is approximately ......days.
10 - 11
12 - 13
13 - 14
none of these
Stars are formed in
Ceres
Nebula
Andromeda
None of these
Proxima Centauri is at a distance of.......light years from the earth.
4.5
4.2
4.6
According to Big Bang theory, all the celestial objects existed at a certain point which is
expanding into the present day universe
contracting into the present day universe
located in the middle of the Milky Way
located in the middle of the Solar System
Sun has nine planets . Which is the largest among all of them ?
Neptune
Jupiter
Earth
Saturn
The gravitational force between two masses m1 and m2, separated by a distance r, is F. The mass m1 is then reduced to three-fourth of its initial value.
To keep the gravitational force constant without changing m2, the separation r should be
increased to r
decreased to r
The force of gravity is____ force that is ______ proportional to the ______ of the distance between the two given masses.The information in which alternative completes the given statement?
a repulsive, inversely , square
a repulsive, directly, cube
an attractive, inversely , square
an attractive, directly , cube
In stars , the hydrogen nuclei convert into helium nuclei by _________ reaction.
Nuclear fission
Mutation
Nuclear fusion
Electron transition