Acdc

Question 1

For a DC generator, when the number of poles and the number of conductors is fixed, which winding will give the highest emf?

Answer 1

LAP WINDING

Question 2

In a DC generator, the generated emf is directly proportional to the?

Answer 2

POLE FLUX

Question 3

An ideal DC generator is one of that has…… Voltage regulation.

Answer 3

ZERO

Question 4

The series field of a long shunt DC generator is excited by……. Current.

Answer 4

LOAD CURRENT

Question 5

The sole purpose of commutator in a DC generator is to?

Answer 5

CONVERT THE INDUCED EMF FROM AC TO DC

Question 6

The yoke of a DC machine is made from which of the following materials?

Answer 6

CAST STEEL

Question 7

What is/are the functions of the pole shoes in a DC machine?

Answer 7

TO SUPPORT THE FIELD COILS
TO SPREAD OUT THE FLUX
TO REDUCE THE RELUCTANCE OF THE MAGNETIC FLUX

Question 8

What is the classification of a DC generator that received it’s field excitation from an internal source?

Answer 8

SELF-EXCITED

Question 9

The current of the armature conductors of a DC generator is?

Answer 9

AC

Question 10

An “Exciting current” is the one that is required in which of the following?

Answer 10

TO CREATE A MAGNETIC FIELD

Question 11

The commercial efficiencyof a DC generator is maximum when it’s variable loss equals to ……….. Loss?

Answer 11

CONSTANT LOSS

Question 12

Which of the following is considered the real working part of a DC generator?

Answer 12

ARMATURE WINDINGS

Question 13

Wave winding is suitable for ……. Current, ……… Voltage DC generators.

Answer 13

LOW, HIGH

Question 14

This is due to the presence of circulating current in the core material?

Answer 14

EDDY CURRENT LOSS

Question 15

DC series generators has ……. Number of turns and ……… Wire having ……… Resistance.

Answer 15

LESS, THICK , LOW

Question 16

The series field of a short- shunt DC generator is excited by …….. Currents.

Answer 16

LOAD CURRENT

Question 17

The armature core of the DC machine is made form which of the following.

Answer 17

SILICON STEEL

Question 18

These are the machines that drives the rotor of a DC generator.

Answer 18

INTERNAL COMBUSTION ENGINE
HYDRAULIC AND STEAM TURBINES,
SYNCHRONOUS MOTORS

Question 19

DC shunt generator has …….. Number of turns and ……… Wire having…….. Resistance.

Answer 19

MORE, THIN, HIGH

Question 20

Collectively, magnetic and mechanical losses are known as ?

Answer 20

STRAY LOSSES

Question 21

It is due to the reversal of magnetization of the armature core as it passes under the north and south pole alternately.

Answer 21

HYSTERESIS LOSSES

Question 22

If the armature of an eight-pole machine were found with wave winding, how many parallel paths would there be?

Answer 22

2 PATHS

Question 23

Welding generator have?

Answer 23

LAP WINDING

Question 24

The function of pole shoes in the case of DC machines is?

Answer 24

-TO REDUCE RELUCTANCE OF THE MAGNETIC PATH
-TO SPREAD OUT THE FLUX TO ACHIEVE UNIFORM FLUX
-TO SUPPORT THE FIELD COIL

Question 25

The resistance of the armature winding depends on?

Answer 25

-LENGTH OF THE CONDUCTOR
-CROSS SECTIONAL AREA OF THE CONDUCTOR
-NUMBER OF CONDUCTORS