As shown in the figure, there are non-conducting hollow sphere and a positive charge q outside.    why does the induction takes place as shown in 1st figure. why not it takes place like 2nd figure? 

induction in a material takes place in order to nullify or oppose externally applied electric field. The first configuration is the way of reperesenting it.

Moreover the electric polarisation is the phenomenon which causes this.

Polarization of Dielectric

If a material contains polar molecules, they will generally be in random orientations when no electric field is applied. An applied electric field will polarize the material by orienting the dipole moments of polar molecules.

This decreases the effective electric field between the plates and will increase the capacitance of the parallel plate structure. The dielectric must be a good electric insulator so as to minimize any DC leakage current through a capacitor.

as far as my understanding, with ur xplanation i understand that on polarization, separation of charge takes place and + ve and -ve charge comes on both the surfaces. that means 2nd figure notation is correct but if so then there will be 2 induced field and they will itself going to cancel each other.

i am still not getting.

Dear Princess,

Here you are absolutely correct in stating the second way, i dont object it, it is right but effectively it is figure one only.

Its just like the series combination of four batteries say 1.5 +1.5 +1.5 + 1.5 = 6 V, is merely represented as a single battery of 6 V, with polarity same as the comination of four batteries.

Hope it is now clear to you.

but how does it happen so..

effectively how does it become lik 1st figure.. 

WELL, FIRSTLY AS IT`S NON-CONDUCTING SPHERES

SO CHARGES HAVE TO BE INSIDE ONLY .

HOW CAN THEY RESIDE ON SURFACE ??????

AS THEY INDICATE FREE ELECTRON

(THIS MEANS THAT MATERIAL IS CONDUCTING BY PROVIDING THE FREE ELECTRON)