Recommended Content

Page 1 :
Contd./- J, , ' l :, , 3. Awire has a resistance R. Find the new resistance,, i. If radius of cross-sectional area of a cylindrical wire is, doubled, then find ratio of initial to final resistance., , it. If length of wire is increased by 10%, then find the percentage increase in, its resistance., , Ans: (i). In both the cases, volume of the wire is same., l, So, V=A,l, =A. >ar7l=n(2r)*l,>bL= z, _ pl _ plz __pl, Now, Ry = mr2 and R2 = Anr2 16mr2, Ri _, , a = 16, R, (ii). Given, l, = |, Ay = A, lp =14+10% of |= 1.11, Ay = A’