55) Full wave Rectifier has theoretical maximum efficiency of

56) Smita, Monica and Reema can type a 50 page document in 4 hrs, if they work together Smita herself can type it in 12 hrs and Reema can do it in 10 Hours. Monica alone can type it in

57) Pyrometer is used to measure

58) A pre-Stressed concrete pile is

59) A candidate who get 20 % marks in the examination fails by 30 marks but another candidate gets 32% marks gets 42 marks more than the minimum pass marks. The pass percentage is