CL wadhwa bits solutions (145 - 149)

Lesson 6 of 26 • 35 upvotes • 15:00mins

Anvesh Sameer

145. If the excitation of the synchronous generator fails, it acts as a: (a) Synchronous motor (b) Synchronous generator (c) Induction motor (d) Induction generator. 146. I and T are the line current and the torque respectively when DOL starter is used, these quantities when Y/Δ starter is used, are: (a) I T 3 3 , (b) I T 3 3 , (c) I T 2 2 , (d) I T 2 4 , . 147. A 100 KVA transformer has 4% impedance and 50 KVA transformer has 3% impedance. When they are operated in parallel, which transformer will reach full load first.   

 (a) 3% (b) 4% (c) The data is insufficient to judge. 148. In EHV transmission lines, efficiency of transmission can be increased by decreasing the corona loss. This is achieved by (a) Increasing the distance between the line conductors (b) Using bundled conductors (c) Using thick conductors (d) Using thin conductors. 149. An alternator having induced emf. of 1.6 p.u. is connected to an infinite bus of 1.0 p.u. If the busbar has reactance of 0.6 p.u. and alternator has reactance of 0.2 p.u., the maximum power that can be transferred is given by (a) 8 p.u. (b) 2 p.u. (c) 2.67 p.u. (d) 5.0 p.u.