Two rods of different materials and identical cross sectional areas, are joined face to face at one end and their free ends are fixed to the rigid walls. If the temperature of the surroundings is increased by 30°C, the magnitude of the displacement of the joint of the rod is (length of rods 1_(1) = 1_(2) = 1 unit, ratio of their young's modulii, y_(1) //y_(2) = 2, coefficients of linear expansion are alpha_(1) and alpha_(2) )

Two rods of different materials and identical cross sectional areas, a

1.	Two rods of different materials and identical cross sectional areas, are joined face to face at one end and their free ends are fixed to the rigid walls. If the temperature of the surroundings is increased by 30°C, the magnitude of the displacement of the joint of the rod is (length of rods 1_(1) = 1_(2) = 1 unit, ratio of their young's modulii, y_(1) //y_(2) = 2, coefficients of linear expansion are alpha_(1) and alpha_(2) )
Answer» ` 5 ( alpha_(2) - alpha_(1) )` `10 ( alpha_(1) - alpha_(2))` `10 ( alpha_(2) - 2 alpha_(1))` `5 ( 2 alpha_(1) - alpha_(2))` Answer :C