Mechanical Prop...

Two wires of different material and radius have their length in ratio of $$1:2.$$ if these were stretched by the same force$$,$$ the strain produced will be in the ratio$$.$$  

$$10^{22}$$ particle each of mass $$10^{-26}Kg$$ are striking perpendicularly on a wall of area $$1m^2$$ with speed $$10^4m/s$$ in $$1sec$$. The pressure on the wall if collisions are perfectly elastic is:

Two elastic wire $$A \& B$$ having length $$\ell_A = 2 \,m$$ and $$\ell_B = 1.5 \,m$$ and the ratio of young's modules $$Y_A : Y_B$$ is $$7:4$$. If radius of wire $$B (r_B)$$ is $$2 mm$$ then choose the correct value of radius of wire $$A$$. Given that due to application of the same force charge in length in both $$A \& B$$ is same

For an equal stretching force F, the Young's modulus $$ (Y_s) $$ for steel and rubber $$ (Y_r) $$ are related as

If $$F$$ is the force applied to an elastic bar to produce an extension of $$\Delta\ell$$. The, the energy lost in the process is 

Pick up the correct statement:

An elastic string of length $$42sm$$ and cross-sectional area $$10^{-4}m^2$$ is attached between two pegs ar distance of $$6mm$$ as shown in the figure. A particle of mass m is kept at midpoint of string and stretched as shown in figure by $$20cm$$ and release. As the string its natural length, the particle attains a speed of $$20m/s$$. Then young modulus $$Y$$ of string is of order

Select the correct alternative $$(s)$$
a) Elastic forces are always conservative
b) Elastic forces are not always conservative
c) Elastic forces are conservative only when Hooke's law is obeyed
d) Elastic forces may be conservative even when Hooke's law is not obeyed

A wire of density 9$$gm/cm^2$$ is stretched between two clamps 1.00 m apart subjected extension of 0.05 cm. The lowest frequency of transverse vibrations in the wire is 
(Assume Young's modulus Y = $$9* 10^10 N/m^2$$)

The relation between Young's modulus $$(Y)$$, bulk modulus $$(K)$$ and modulus of elasticity $$(n)$$ is