If the line of sight between two stations A and B, on sea, and 80 km apart, makes tangent at point A, then the minimum elevation of the signal required at B (considering the coefficient of refraction "m" = 0.08 and the mean radius of earth as 6400 km) will be

A simply supported beam of uniform cross-section is subjected to a maximum bending moment of 2.25 t.m. If it has rectangular cross-section with width 15 cm and depth 30 cm, then the maximum bending stress induced in the beam will be

Consider the following statements regarding underreamed piles : 1. They are used in expansive soils. 2. They are of perkcast reinforced concrete. 3. The ratio of bulb to shaft diameters is usually 2 to 3. 4. Minimum spacing between the piles should not be less than 1.5 times the bulb diameter. of these statements :

Consider the following statements regarding a beam of uniform cross-section simply supported at its ends and carrying a concentrated load at one of its third points : 1. Its deflection under the load will be maximum. 2. The bending moment under the load will be maximum. 3. The deflection at the mid-point of the span will be maximum. 4. The slope at the nearer support will be maximum. Of these statements :