19. The difference between the synchronous speed and the actual speed of an mduction motor is
known ‏؛ ٥‎

(५) अफ (8) regulation (Cy black lash (D) 8

20, Three resistances of 30, 15, 5, ohms are connected in parallel, their combined resistance will

be:
(५) greater than 30 ohm (ए) between 30 to 15 ohm
(८) less than 5 ohm (10) between 13 to 5 chm

21, Which of the following acts as a depolarizer in a drv 817
(ക) zine chloride (ए) வண்ண powder

‎ amumonium chloride (D) manganese dioxide‏ مت

‎22, Efficiency of a power transformer is of the order of :

‎(ക) 50% (൫) 75% (८) 98% (D) 45%

‎23, The strongest dia-magnetic material :

‎{A) sulphur (8) bismuth (C) ஜூ (D) graphite

‎: The magnitude of torque developed by a three phase induction motor depends upon :
(A) rotor current, rotor ೮1೫, 10107 pf
(8) supply voltage, stator current, frequency
(C) number of poles, speed, frequency

‎(0) synchronous speed, rotor speed, frequency

‎25. Rheostat method of speed control of induction moter is used in :

‎(A) squirrel cage IM (B) slip ring IM (೮) double cage IM (ற) all of the above

‎26. In a three phase IM the number of poles in the rotor winding are :
(A) दशाण (8) 1९55 पया तना poles

‎(യ) equal to stator poles (D) more than stator poles

‎5 152/2016
௦)

‎