A metal sphere is hung by a string fixed to a wall. The forces acting on the sphere are shown in figure. Which of following statements are correct:

[a] For equilibrium of sphere, vector sum of all the forces must be zero. Hence N−→+T→+W−→−=0. Also by componenting, Tcosθ=W  and Tsinθ=N. Hence T2=W2+N2 and N=Wtanθ