When UV light of wavelength $$300 \mathrm{~nm}$$ is incident on the metal surface having work function $$2.13 \mathrm{~eV}$$, electron emission takes place. The stopping potential is :

(Given hc $$=1240 \mathrm{~eV} \mathrm{~nm}$$ )

Match List I with List II:

	LIST I (Y vs X)		LIST II (Shape of Graph)
A.	Y-magnetic susceptibility X = magnetising field	I.
B.	Y = magnetic field X = distance from centre of a current carrying wire for x < a (where a = radius of wire)	II.
C.	Y = magnetic field $$\mathrm{X}=$$ distance from centre of a current carrying wire for $$x>\mathrm{a}$$ (where $$\mathrm{a}=$$ radius of wire)	III.
D.	Y = magnetic field inside solenoid X = distance from centre	IV.

Choose the correct answer from the options given below :

For the thin convex lens, the radii of curvature are at $$15 \mathrm{~cm}$$ and $$30 \mathrm{~cm}$$ respectively. The focal length the lens is $$20 \mathrm{~cm}$$. The refractive index of the material is :

Two identical conducting spheres P and S with charge Q on each, repel each other with a force $$16 \mathrm{~N}$$. A third identical uncharged conducting sphere $$\mathrm{R}$$ is successively brought in contact with the two spheres. The new force of repulsion between $$\mathrm{P}$$ and $$\mathrm{S}$$ is :