Elastic And Plastic Deformation

Item Code: SK050

Principle and Working:

The ratio of the normal stress to the longitudinal strain is called Young's modulus of elasticity. If a wire of length 's' and area of cross section 'a' be stretched by a force F and if a change (Increase) of length Δs is produced , then
... Normal stress =F/a, Longitudinal strain, ε= Δs /s
Modulus of elasticity, E= Normal stress/ longitudinal strain.
In the present setup the extension produced is magnified by 40 times for easy observation on a pointer scale.




  • A precision pointer indicator measures the change in length Δs, i. e. the extension.
  • Modular Approach.
  • Sample wire different material.
  • Double hook weight increase the weight in steps corresponding measure the wire extension .
  • Different length of wires can be used.

  • To investigate the elastic and plastic extension of metal wires

  • A Base : Cast iron, Length 200 mm, Support rod upto 8-14 mm
  • Metal Wire : Copper 34 SWG, Constantan 34 SWG
  • Scale : Acrylic, 1 div=0.25mm, Pointer Aluminium, length = 200 mm
  • Double Hooke : Brass, Chrome Plated, Fixed double type
  • Mass hook, Capacity 50g.
  • Boss Head : Aluminium alloy, Type Square & round, Object size Up-to 13mm dia
  • Support Rod : Mild Steel L=100cm, L=50cm, L= 25cm Dia. 10mm
    • 1 Rod 1m
    • 2 Rod, 50 cm
    • 1 Rod, 35 cm
    • 2 Rod, 25 cm
    • 2 A’ shaped base
    • 5 Bosshead
    • 3 Clamp block
    • 1 Cu wire
    • 1 Constantan wire
    • 1 Pulley with Banana Plug
    • 1 Pointer Assembly
    • 1 Acrylic Dual Scale Screen
    • 1 Plug 4mm
    • 24 Double hooked mass 50g