Two spheres of same size are made of the same metal but one is hollow and the other is solid. They are heated to same temperature, then

Calculation:

When two spheres made of the same metal are heated to the same temperature, the coefficient of linear expansion is the same for both spheres. 

The formula for volume expansion is given by:

ΔV = γ · V₀ · ΔT

For the solid sphere:

ΔV_solid = γ · V_solid · ΔT

For the hollow sphere:

ΔV_hollow = γ · V_hollow · ΔT

ΔV_solid = ΔV_hollow

Hence, the correct answer is Option 1: both spheres will expand equally