309) Consider the following statements: Automatic signalling system results in 1.greater risk 2.higher efficiency 3.avoidance of block instruments 4.higher operating cost Of these statements

310) Wear of rails is maximum in weight of

311) A train is hauled by 2-8-2 locomotive with 22.5 tonnes and on each driving axle. Assuming the coefficient of rail-wheel friction to be 0.25, what would be the hauling capacity of the locomotive

312) A treadle bar is used for

313) Consider the following statements about concrete sleepers. 1.They improve the track modulus. 2.They have good scrap value. 3.They render transportation easy. 4. They maintain the gauge quite satisfactorily. Of these statements