1. MOV protection in a UPS system is used for which of the following? 1. Protection against overload current 2. Protection against high input voltage 3. Protection against frequency variations 4. Protection against temperature variations   ANS- 2 2.Which of the following best defines the effect of corona on a power line? 1. The diameter of the conductor remains the same, whereas the electrostatic stress is decreased. 2. The virtual diameter of the conductor is decreased and the electrostatic stress is increased. 3. The diameter of the conductor is increased but the electrostatic stress remains the same. 4. The virtual diameter of the conductor is increased and the electrostatic stress is decreased. ANS-4 3.Which of the following statements are correct for planned preventive maintenance? (i)Overtime costs are reduced (ii)Improves the safety and health of workers (iii)Reduced number of repairs (iv)Improper usage of manpower 1. Only ii, iii and iv 2. Only i, ii and iv 3. Only i, ii ...