84,

85,

86,

87.

88,

89,

90,

91,

92,

Select a suitable motor for continuous rolling mills.
(A) DC shunt motor

(8) 3 phase slip ring induction motor

(ಲ) 3 phase squirrel cage induction motor

(D) 3 phase synchronous motor

The device used to collect the current from over head conductor for electric traction service is

(ಹ) Phantograph (8) Phonograph (ಲ) Phantogram (D) Phonogram

The speed-time characteristics of city service in electric traction system has no
period.

(ಹ) Coasting (8) Acceleration (ಲಿ) Freerunning (D) Breaking

A gate current of 25 mA is applied to turn on an SCR. Anode current flowing through this
SCR is found to be 100 A. What will be the Anode current through the SCR if the gate
current is reduced gradually to 10 mA. The holding current of this SCR 15 10 mA.

(ಹಿ) Zero (B 50A © 100 A (D) 200 A

The power electronics device which converts constant dc voltage to variable dc voltage is
called

(ಹ) Inverter ) UPS (ಲ) Chopper (D) SCR

How many number of SCRs are required for constructing a single phase semi converter
circuit ?

@) 1 ® 2 © 3 o 6
Buck converter is used as a converter.
(^) Step up (8) Step down (ಲ) Isolation (D) None of these

Calculate the back pitch of the simplex progressive lap winding with 24 slot and 4 pole dc
armature with 24 commutator segments.

@A) 6 ® 12 © 13 യു 15
Cruciform construction of a transformer core consists of number of steps.
കാ ® 2 © 3 2 4

13 029/2018

1.7.೦.