Related Questions

The emf generated in a dc generator is directly proportional to
A Flux per pole
B No, of oples
C Spped of armature
D all above
The e.m.f. generated by a shunt wound D.C. generator is E. Now while pole flux remains constant, if the speed of the generator is doubled, the e.m.f. generated will be
A $$\frac{{\text{E}}}{2}$$
B 2E
C Slightly less than E
D E
If A varies directly proportional to C and B also varies directly proportional to C, which one of the following is not correct ?
A $$\left( {A + B} \right)\alpha \,C$$
B $$\left( {A - B} \right)\alpha \,\frac{1}{C}$$
C $$\sqrt {AB} \,\alpha \,C$$
D $$\frac{A}{B} = {\text{constant}}$$
Which of the following relates the emf. generated in a single homogeneous wire to the temperature difference?
A Peltier effect
B Thomson effect
C Seebeck effect
D None of these
An emf of the order of mV is generated when two solutions of different hydrogen ion concentration are separated by a thin glass wall. This is the working principle of a
A PH meter
B Polarimeter
C Chromatograph
D Polarograph
Out of the following, the highest emf for a given temperature is generated by the __________ thermocouple.
A Chromel - alumel
B Iron - constantan
C Platinum - platinum + rhodium
D Copper-constantan
Emf generated in a thermocouple depends on the temperature
A Of cold junction only
B Of hot junction only
C Difference between hot and cold junctions
D Difference between cold junction and atmospheric temperature
A separately excited generator as compared to a self-excited generator
A Is amenable to better voltage control
B Is more stable
C Has exciting current independent of load current
D Has all above features
Which of the following components of a D.C, generator plays vital role for providing direct current of a D.C. generator?
A Dummy coils
B Commutator
C Eye bolt
D Equalizer rings
The losses occurring in a D.C. generator are given below. Which loss is likely to have highest proportion at rated load of the generator?
A Hysteresis loss
B Field copper loss
C Armature copper loss
D Eddy current loss

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