11.A rectangular block of size 200 mm x 100 mm x 50 mm is subjected to a shear stress of 100 N/mm2. If modulus of rigidity of material is 1 x 105 N/mm2, strain energy stored will be

12.A three hinged parabolic arch rib is acted upon by a single load at the left quarter point. If the central rise is increased and the shape of arch altered to segmental without changing the other details, the horizontal thrust will

13.Impact test enables one to estimate the property of

14.The property of metal which allows it to deform continuously at slow rate without any further increase in stress is known as

15.Method of joints is applicable only when the number of unknown forces at the joint under consideration is not more than