70) In order to reduce hysterisis losses the core of electrical machines are generally made of

71) The speed of Energy meter can be controlled by

72) What is the material used inside the breather to prevent the moisture entering the transformer?

73) If 10% of a number is 30, what is the number?

74) A ladder is kept leaning against a wall such that its tip is along the top of the wall. Length of the ladder is 13 m. The height of the walls is 12m. What is the distance between the base of the wall and the foot of the ladder?