When a closely-coiled helical spring of mean diameter (D) is subjected to an axial load (W), the stiffness of the spring is given by

A. Cd⁴/D3n

B. Cd⁴/2D3n

C. Cd⁴/4D3n

D. Cd⁴/8D3n

Please do not use chat terms. Example: avoid using "grt" instead of "great".

You can do it
  1. The layer at the centre of gravity of the beam as shown in the below figure, will be
  2. The molecular mass expressed in gram (i.e. 1 g - mole) of all gases, at N. T. P., occupies a volume…
  3. During a tensile test on a specimen of 1 cm cross-section, maximum load observed was 8 tonnes and area…
  4. Which of the following statement is correct?
  5. When a body is subjected to biaxial stress i.e. direct stresses (σx) and (σy) in two mutually…
  6. Which of the following cycles is not a reversible cycle?
  7. Otto cycle efficiency is higher than Diesel cycle efficiency for the same compression ratio and heat…
  8. Which of the following statement is correct according to Clausis statement of second law of thermodynamics?
  9. The entropy __________ in an irreversible cyclic process.
  10. The oxygen atom is ________ times heavier than the hydrogen atom.
  11. Mond gas is obtained by
  12. The compression ratio for Diesel engines is
  13. The section modulus of a circular section about an axis through its C.G., is
  14. The strain energy stored in a body due to suddenly applied load compared to when it is applied gradually…
  15. The general law of expansion or compression is pvn = C, The process is said to be hyperbolic, if n is…
  16. The efficiency of Carnot cycle depends upon
  17. When both ends of a column are fixed, the effective length is
  18. The ratio of specific heat at constant pressure (cp) and specific heat at constant volume (cv) is
  19. The heat and work are mutually convertible. This statement is called __________ law of thermodynamics.
  20. The area under the temperature-entropy curve (T - s curve) of any thermodynamic process represents
  21. The stress induced in a body due to suddenly applied load compared to when it is applied gradually is
  22. The principal constituents of a fuel are
  23. Which of the following statement is wrong?
  24. The strain energy stored in a solid circular shaft in torsion, subjected to shear stress (τ), is:…
  25. A boiler shell 200 cm diameter and plate thickness 1.5 cm is subjected to internal pressure of 1.5 MN/m,…
  26. Youngs modulus of a wire is defined as the stress which will increase the length of wire compared to…
  27. Carbonisation of coal consists of
  28. A concentrated load is one which
  29. The efficiency of Stirling cycle is __________ Carnot cycle.
  30. The entropy may be expressed as a function of