lf a heavy point mass is suspended by a weightless, inextensible and perfectly flexible string from a rigid support, then this arrangement is called simple pendulum.
In practice, however, these requirements cannot be fulfilled. So we use a practical pendulum.
A practical pendulum consists of a small metallic solid sphere suspended by a fine silk thread from a rigid support. This is the practical simple pendulum which is nearest to the ideal simple pendulum.
Note :
The metallic sphere is called the bob.
When the bob is displaced slightly to one side from its mean position and released, it oscillates about its mean position in a vertical plane.
Answer:
So the distance of the antenna from the station will be 3.018 m
Explanation:
We have given the frequency of the broadcast 
The speed of light 
The distance of the antenna to receive a minimum signal from the station is given by 
So the distance of the antenna from the station will be 3.018 m
The International Astronomical Union (IAU) downgraded the status of Pluto to that of a dwarf planet because it did not meet the three criteria the IAU uses to define a full-sized planet. Essentially Pluto meets all the criteria except one—it “has not cleared its neighboring region of other objects.
Answer: (b)0.000012/k
Explanation:
The linear expansion of the metal rod is given by

where
is the linear expansion
is the initial length of the rod
is the linear expansivity
is the increase in temperature
By re-arranging the equation, we find the linear expansivity:

No because it will contain the same amount of mass, just in different forms.