A) 2000 N B) 1000 N C) 500 N D) 250 N
as you know that young's modulus = (tension*original length)/(cross sectional area*change in length) since in this question all the quantities except tension and area are constant we can say that tension∝area of cross section. thus tension∝D² (as area = πD²/4 ; D is diameter) so if for D =1 tension = 500N then for D = 2 tension will be four times i.e tension = 2000N.