A plate with an elliptical hole in the centre, with semi-major axis (a) perpendicular to the direction of loading and semi-minor axis (b) along the direction of loading, is subjected to a pull P. The maximum stress induced at the edge of the hole is equal to (where σ = Stress for a plate with no hole i.e. nominal stress)

• A. σ [1 + (b/2a)]
• B. σ [1 + (b/3a)]
• C. σ [1 + (3a/b)]
• D. σ [1 + (2a/b)]

Answer: (D)