DC Generator Objective Type Question Answer

81. Due to armature reaction, the main pole flux of a d.c. generator is

(i) weakened only
(ii) distorted only
(iii) weakened as well as distorted
(iv) none of the above

(i) magnetic
(ii) internal
(iii) external
(iv) performance

83. The line representing the critical resistance of a d.c. generator ……. its O.C.C.

(i) intersects
(ii) runs parallel to
(iii) just touches
(iv) none of the above

84. Which of the following generator provides approximately constant voltage from no-load to full-load ?

(i) series
(ii) shunt
(iii) flat-compounded
(iv) over-compounded

85. A shunt generator gives its greatest voltage at

(iv) none of the above

86. The level of compounding in a cumulatively compounded d.c. generator is generally adjusted by

(i) changing series field current
(ii) changing shunt field current
(iii) connecting it long-shunt
(iv) connecting it shod-shunt

87. The d.c. generator that has poorest voltage is

(i) shunt generator
(ii) over-compounded generator
(iii) flat-compounded generator
(iv) series generator

(i) f = NP/120
(ii) f = NP/60
(iii) f = NP/240
(iv) f = NP/30

89. If the value of shunt field resistance of a shunt generator is greater than the critical resistance, the generator will

(i) excite to full voltage
(ii) fail to excite
(iii) excite to one-half of full-voltage
(iv) none of the above

(i) 4.5%
(ii) 11.3%
(iii) 2.8%
(iv) 9.1%

(i) internal
(ii) external