Two rods are joined between fixed supports as shown in the figure. Condition for no change in the lengths of individual rods with the increase of temperature will be (\[{{\alpha }_{1}},{{\alpha }_{2}}\]= linear expansion co-efficient \[{{\text{A}}_{\text{1}}}\text{,}{{\text{A}}_{\text{2}}}\] =Area of rods \[{{\text{Y}}_{\text{1}}}\text{,}{{\text{Y}}_{\text{2}}}\]= Young modulus)

• A. \[\frac{{{\text{A}}_{\text{1}}}}{{{\text{A}}_{\text{2}}}}\text{=}\frac{{{\text{ }\!\!\alpha\!\!\text{ }}_{\text{1}}}{{\text{Y}}_{\text{1}}}}{{{\text{ }\!\!\alpha\!\!\text{ }}_{\text{2}}}{{\text{Y}}_{\text{2}}}}\]
• B. \[\frac{{{\text{A}}_{\text{1}}}}{{{\text{A}}_{\text{2}}}}\text{=}\frac{{{\text{L}}_{1}}{{\text{ }\!\!\alpha\!\!\text{ }}_{\text{1}}}{{\text{Y}}_{\text{1}}}}{{{\text{L}}_{2}}{{\text{ }\!\!\alpha\!\!\text{ }}_{\text{2}}}{{\text{Y}}_{\text{2}}}}\]
• C. \[\frac{{{\text{A}}_{\text{1}}}}{{{\text{A}}_{\text{2}}}}\text{=}\frac{{{\text{L}}_{2}}{{\text{ }\!\!\alpha\!\!\text{ }}_{2}}{{\text{Y}}_{2}}}{{{\text{L}}_{1}}{{\text{ }\!\!\alpha\!\!\text{ }}_{1}}{{\text{Y}}_{1}}}\]
• D. \[\frac{{{\text{A}}_{\text{1}}}}{{{\text{A}}_{\text{2}}}}\text{=}\frac{{{\text{ }\!\!\alpha\!\!\text{ }}_{2}}{{\text{Y}}_{2}}}{{{\text{ }\!\!\alpha\!\!\text{ }}_{1}}{{\text{Y}}_{1}}}\]