EE 311-Pre-SetB

```EE 414 – Energy Conversion 1
Prelim Examination
Name: ______________________________________________________
Rating : ____________
Test I. Multiple Choice. Select the correct answer.
1. Find the armature current of dc shunt generator whose shunt field current is 40 A and load circuit of 400 A.
a) 380 A
b) 400 A
c) 420 A
d) 440 A
2. A 4-pole dc generator with duplex wave winding has 48 slot and four elements per slot. The flux per pole is
2.5 x 10 6 maxwells and it runs at 1500 rpm. What is the output voltage?
a) 60 V
b) 120 V
c) 225 V
d) 360 V
3. Which of the following is not a requirements for successful parallel operation of generators.
a) Same polarity
b) Same voltage
c) Same internal characteristics
d) As much as possible same speed droop characteristics.
4. In a 12-pole duplex wave wound dc armature, each conductor can carry a current of 50 amperes.
What is the rated current of the armature?
a) 200 A
b) 600 A
c) 1200 A
d) 2400 A
5. If the armature of an eight-pole machine were wound with a triplex wave winding, how many parallel paths
would there be?
a) 24 paths
b) 16 paths
c) 12 paths
d) 6 paths
6. The generated emf in a dc generator is directly proportional to
a) flux
b) speed
c) parallel paths
d) both a &amp; b
7. A 2-pole duplex-lap dc machine has 400 conductors in its armature and is driven at 300-rpm. Calculate the
generated EMF if the flux is 0.1 Wb.
a) 100 V
b) 200 V
c) 300 V
d) 400 V
8. If each conductor of an 8-pole simplex-lap armature winding can carry a current of 100-A. Calculate the
current capacity of this machine.
a) 200 A
b) 400 A
c) 800 A
d) 1600 A
9. A shunt generator delivers a load current of 500 A at a terminal voltage of 230 V. If the shunt field resistance
and armature resistance are 50-Ω and 0.02-Ω respectively, calculate the armature’s generated emf.
a) 225 V
b) 230 V
c) 235 V
d) 240 V
10. A generator with 1.6 Ω armature circuit resistance has a terminal voltage of 125 V when the armature current
is 8 A. Assuming that the generated voltage does not change, find the terminal voltage when the armature
current is 18 A.
a) 104.0 V
b) 109.0 V
c) 132.8 V
d) 137.8 V
Test II. Problem Solving. Show your solution.
1. In a short compound generator, the terminal voltage is 230 V when generator delivers a 150 A.
Determine a) Induced (generated) emf , b) total power generated and c) Power delivered. Given that
the shunt field, series field, diverter and armature resistances are 92 Ω, 0.015 Ω, 0.03 Ω and 0.032 Ω resp
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