JAMB Physics 1992 Question 10

Question 10

Elasticity

In an experiment to determine Young's Modulus for a wire, several loads are attached to the wire and the corresponding extensions measured. The tensile stress in each case depends on the

  1. A.load and the extension
  2. B.load and the radius of the wire
  3. C.radius of the wire and the extension
  4. D.extension and the original length of the wire
Show the answer and explanation

Answer: B (load and the radius of the wire)

Explanation

Tensile stress = force ÷ cross-sectional area = load ÷ πr², so it depends on the load and the radius of the wire.