11ya forgot about that...shit one more wrong...
Consider a large hollow sphere of radius 'R' in which small solid sphere of radius 'r' has to be placed in closest pascking. ( assume r=R/10)
1) Maximum no. of small spheres that can be filled into the large hollow sphere are :
a)1000 b)500 c)250 d)740
2) If small spheres are to be placed in a square of edge R , then how many spheres ( whose centres will lie on or inside the square 0 are possible. ( assume the packing to be 2D square packing )
a) (R+10)2/100 b) R2/100 c) ( R+11)2 / 100 d) 99R2/100
3) If a cube is made such that small spheres are at the corners and large sphere is at the body centre of the cube , then whats the packing fraction of the system ?
a)0.68 b) 0.74 c)0.52 d)o.002
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6 Answers
11See total volume of big sphere = 4∩R3/3
Small sphere volume = 4∩R3/3000
Therefore N = 4∩R3/3/4∩R3/3000
N = 1000
19what i can say is that we find out the void space after the small spheres occupy all the space and then differentiate it to find its minimum value ! [1]