In an experiment, brass and steel wires of length 1 m each with areas of cross section $1 \mathrm {~mm} ^ { 2 }$ are used. The wires are connected in series and one end of the combined wire is connected to a rigid support and other end is subjected to elongation. The stress required to produce a net elongation of 0.2 mm is, [Given, the Young's Modulus for steel and brass are, respectively, $120 \times 10 ^ { 9 } \mathrm {~N} / \mathrm { m } ^ { 2 }$ and $60 \times 10 ^ { 9 } \mathrm {~N} / \mathrm { m } ^ { 2 }$ ] (1) $8.0 \times 10 ^ { 6 } \mathrm {~N} / \mathrm { m } ^ { 2 }$ (2) $1.2 \times 10 ^ { 6 } \mathrm {~N} / \mathrm { m } ^ { 2 }$ (3) $0.2 \times 10 ^ { 6 } \mathrm {~N} / \mathrm { m } ^ { 2 }$ (4) $1.8 \times 10 ^ { 6 } \mathrm {~N} / \mathrm { m } ^ { 2 }$
In an experiment, brass and steel wires of length 1 m each with areas of cross section $1 \mathrm {~mm} ^ { 2 }$ are used. The wires are connected in series and one end of the combined wire is connected to a rigid support and other end is subjected to elongation. The stress required to produce a net elongation of 0.2 mm is, [Given, the Young's Modulus for steel and brass are, respectively, $120 \times 10 ^ { 9 } \mathrm {~N} / \mathrm { m } ^ { 2 }$ and $60 \times 10 ^ { 9 } \mathrm {~N} / \mathrm { m } ^ { 2 }$ ]\\
(1) $8.0 \times 10 ^ { 6 } \mathrm {~N} / \mathrm { m } ^ { 2 }$\\
(2) $1.2 \times 10 ^ { 6 } \mathrm {~N} / \mathrm { m } ^ { 2 }$\\
(3) $0.2 \times 10 ^ { 6 } \mathrm {~N} / \mathrm { m } ^ { 2 }$\\
(4) $1.8 \times 10 ^ { 6 } \mathrm {~N} / \mathrm { m } ^ { 2 }$