Match
the items in List I with those of List II and select your answers using the
codes given in the lists :
List
I List II
(Type of duty)
(Applications)
(A) Continuous duty 1. Machine tools
(B) Short time duty 2. Sirens
(C) Continuous duty 3. Blowers
with
intermittent
periodic
loading
(D) Continuous duty 4. Conveyors
with
starting and braking
A
pole-changing squirrel cage induction motor employed in derricks has four,
eight and twenty four pole. The lowest speed is used in :
A
locomotive exerts a tractive effort of 35,300 N in hauling a train at 48 km/h
on the level track. If the motor is to haul the same train on a gradient of 1
in 50 and the tractive effort required is 55,180N determine the power delivered
by the locomotive if it is driven by (i) dc series motors (ii) induction motors,
The
approximate continuous rating of a motor for a load of 100 HP for 20 minutes at
3/4th load for next 10 minutes and a no
load for next 20 minutes is :
In AC locomotives, squirrel cage induction motors are used, the method of speed control is :
An
electric train taking of constant current of 600A moves on a section of line
between two substation 8 km apart maintained at 575V and 590V respectively. The
track resistance is 0.04 Ohm per km both go and return. The point of minimum
potential along the track is at a distance from 575V substation is
A
motor has to be selected for following load cycle. Load uniformly rising from
zero to 100 hp in 10 minutes after which it is constant at 100 hp for the next
10 minutes, followed by no load period of 30 minutes. Suitable size of
continuous rated motor is :
An electric train employing a d.c. series motor is running at a fixed
speed. When a sudden drop in voltage of supply takes place, then this results
in_________.
A
low frequency supply is given to the singlet phase AC system for track
electrification because