Answer:
(B) 1.41 x 10^{10} N/m^{2}
Explanation:
diameter of wire (d) = 0.6 mm = 0.0006 m
radius of wire (r) = 0.0006/2 = 0.0003 m
tension (force F) = 20 N
percentage strain = 0.5 %
what is the Young's modulus?
Young's modulus = [tex]\frac{stress}{strain}[/tex]
where
    stress = [tex]\frac{force}{πr^{2}}[/tex]
    stress = [tex]\frac{20}{πx0.0003^{2}}[/tex]
    stress =70735530.3 N/m^{2}
    strain = 0.5 ÷ 100 = 0.005
therefore Young's modulus = [tex]\frac{stress}{strain}[/tex] =[tex]\frac{70735530.3}{0.005}[/tex] = 1.41 x 10^{10} N/m^{2}