A. List the factors that determine the starting torque of the three-phase induction motor. How does this torque generally compare with the value of the rated torque? B. The low-voltage release of an a.c. motor-starter consists of a solenoid into which an iron plunger is drawn against a spring. The resistance of the solenoid is 35 ohm. When connected to a 220 V, 50 Hz, a.c. 3supply the current taken is at first 2A, and when the plunger is drawn into the “full-in” position the current falls to 0.7 A. Calculate the inductance of the solenoid for both positions of the plunger, and the maximum value of flux-linkages in weber-turns for the “full-in” position of the plunger.

Comments

Post a Comment

Popular posts from this blog

EM MEO Class 1 Written Question (JAN 2023)

EXAMINATION OF MARINE ENGINEER OFFICER ENGINEERING MANAGEMENT M.E.O CLASS – I TIME - 3 HOURS  Total Marks – 100 Q1. Improvements in Rudder efficiency can considerably contribute to improving propulsion   effectiveness. Discuss common rudder-efficiency improvements devices/ techniques currently in use,   referring to the following: (a) Rudder Thrust Fins (b) Asymmetric Rudders (c) Rudder Bulbs (d) Grim Vane Wheels Q2 . a) Briefly discuss Anti fouling convention and state all Documents and records to be maintained on a ship to demonstrate Anti fouling convention compliance. c) Discuss various alternatives to tin-based antifouling paints, with specific reference to the following   types: - (i) Controlled Depletion Polymer (CDP) paint; (ii) Self-Polishing Copolymer (SPC) paint; (Ill) Hybrid TBT free paint ; (iv) Fouling Release paint. Q3 . State the different types of marine insurance policies that could be taken by owners, shippers or   other related parties....
Read more