52) A circuit that is used to protect a voltage-sensitive load from excessive d.c power supply output voltages is called

53) A 3-phase star-connected alternator supplies a load of 10 MW at power factor of 0.85 lagging and at 11 kV terminal voltage. Its resistance is 0.1 Ohm/phase and synchronous resistance 0.66 Ohm/phase. What is the line e.m.f. generated?

54) In isometric drawing, the three mutually perpendicular edges of a cube are at an angle of A. 120 degree B. 90 degree C. 18 degree Which of the above given is/are correct?

55) The sharp corners of the bolt head and nut are chamfered at _____ degree to the flat faces.

56) A _____ view will be useful as a guide in assembling the part of the machine itself.