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The mechanical power developed by a shunt motor will be maximum when the ratio of back
e.m.f, to applied voltage is :

(ಗಿ) 4 ഭു 2 © 1 (D) 05

The e.m.f. induced in the armature of a shunt generator is 240 V. The armature resistance is
0.8 £2. If the armature current is 10 A, the terminal voltage will be :

(५) 7۷ (8) 240V (©) 232% (D) 160V

The speed of a DC shunt motor can be increased by :
(A) Increasing the resistance in the field circuit

(8) Reducing the resistance in the field circuit

(9 Reducing the armature resistance

(D) None of the above

At full load, the copper loss and iron loss in a 100 kVA transformer 15 each equal to 3 kW.
What is the efficiency at a load of 60 kVA, 0.8 power factor ?

(^) 88.889 (8) 90.9% (9) 80.6% (0) 92.16%

An 8 pole DC generator has 500 armature conductors and has a useful flux/pole of
0.065 Wb, What will be the e.m.f. generated it is lap connected and runs at 1000 r.p.m. ?

(ಗಿ) 54167 % (8) 2166.67 ೫% )© ‏۷٣‎ (>) 270.83 7
An over excited synchronous motor will take current at :

(^) lagging p.f. (B) leading ‏عم‎

(0) ‏ام نس‎ (D) none of the above

The V curves of a synchronous motor show relationship between :
(A) armature current and supply voltage

(B) field current and p.f.

(C) armature current and back e.m.f.

(D) de field current and ac armature current

If in a 3 phase 3.5 MVA, 4160 V slar connected alternator, a field current of 200 A produces
full load current on short circuit and 4750 V on open circuit, its synchronous impedance is :

(4) 9.77 ¢ 8 23.75 0 (€) 56402 12) 1370

What is the r.m.s. value of the induced e.m.f. per phase of a 10 pole, 3 phase, 50 Hz alternator
with 2 slots per pole per phase and 4 conductors per slot in two layers ? The coil span is 150°
Flux per pole is 0.12 Wb,

(ക) 560% (ठ) ۷ (€ 1000V (D) 835V

117/2014 6 A