Two wires each of radius 0.2 cm and negligible mass, one made of steel and the other made of brass are loaded as shown in the figure. The elongation of the steel wire is __________ $$\times$$ 10$$^{-6}$$ m. [Young's modulus for steel = 2 $$\times$$ 10$$^{11}$$ Nm$$^{-2}$$ and g = 10 ms$$^{-2}$$ ]

An air bubble of diameter $$6 \mathrm{~mm}$$ rises steadily through a solution of density $$1750 \mathrm{~kg} / \mathrm{m}^{3}$$ at the rate of $$0.35 \mathrm{~cm} / \mathrm{s}$$. The co-efficient of viscosity of the solution (neglect density of air) is ___________ Pas (given, $$\mathrm{g}=10 \mathrm{~ms}^{-2}$$ ).

A metal block of mass $$\mathrm{m}$$ is suspended from a rigid support through a metal wire of diameter $$14 \mathrm{~mm}$$. The tensile stress developed in the wire under equilibrium state is $$7 \times 10^{5} \mathrm{Nm}^{-2}$$. The value of mass $$\mathrm{m}$$ is _________ $$\mathrm{kg}$$. (Take, $$\mathrm{g}=9.8 \mathrm{~ms}^{-2}$$ and $$\pi=\frac{22}{7}$$ )

A steel rod has a radius of $$20 \mathrm{~mm}$$ and a length of $$2.0 \mathrm{~m}$$. A force of $$62.8 ~\mathrm{kN}$$ stretches it along its length. Young's modulus of steel is $$2.0 \times 10^{11} \mathrm{~N} / \mathrm{m}^{2}$$. The longitudinal strain produced in the wire is _____________ $$\times 10^{-5}$$