If the ratio of diameters, lengths and Young's modulus of steel and copper wires shown in the figure are p, q and s respectively, then the corresponding ratio of increase in their lengths would be

As Y=FLAΔL=4FLπD2ΔL ΔL=4FLπD2Y ∴  ΔLSΔLC=FSFCLSLCDC2DS2YCYS  where subscripts S and C refer to copper and steel respectively. Here, FS=(5m+2m)g=7mg FC=5mg LSLC=q,DSDC=p,YSYC=s ∴  ΔLSΔLC=7mg5mg(q)1p21s=7q5p2s