cont(a) 2 N(b) 4N(c) 5 N(d) 7.5 NTwo copper wires of length 1 and 21 have radii r and 2r respectivelorThe ratio of their specific resistances is(b) 2:1

Two copper wire of length l and 2l have radii, r and 2r respectively. What si the ratio of their specific resistance.?

Two copper wire of length l and 2l have radii, r and 2r respectively. What si the ratio of their specific resistance.?

Two wires of same material and length have the radii of their cross sections as r and 2r, respectively. The ratio of their resistances

There are two long co-axial solenoids of same length l. The inner and other coils have redii r_(1) and r_(2) and number of turns per unti length n_(1) and n_(2) respectively .The reatio of mutual inductance to the self - inductance of the inner- coil is : (A) n_(1)/n_(2) (B) n_(2)/n_(1).r_(1)/r_(2) (C) n_(2)/n_1.r_2^2/r_1^2 (D) n_(2)/n_(1)

Choose correct alternative. Two wires have their lengths in the ratio 5:3 and radii in the ratio 1: 2 . Ratio of their resistivity is 3: 4 . The ratio of resistance is