The counter (or back) emf in a dc machine is 1. the same as generated emf in a dc motor 2. proportional to field flux and armature speed 3. not the same as generated emf in a dc motor 4.inversely proportional to field flux 5. proportional to number of armature conductors 6. constant from no load to full load From these, the correct answer is

Electrical Machines
The counter (or back) emf in a dc machine is 1. the same as generated emf in a dc motor 2. proportional to field flux and armature speed 3. not the same as generated emf in a dc motor 4.inversely proportional to field flux 5. proportional to number of armature conductors 6. constant from no load to full load From these, the correct answer is

2, 3, 6

3, 4, 5

2, 4, 5, 6

1, 2, 5

2, 3, 6

3, 4, 5

2, 4, 5, 6

1, 2, 5

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
In normal dc machines operating at full-load conditions, the most powerful electromagnet is

interpole winding

field winding

armature winding

interpole and compensating windings together

interpole winding

field winding

armature winding

interpole and compensating windings together

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
A 500 V, 120 KW, 50 Hz, star connected synchronous motor operating at 0.8 power factor leading has full load efficiency of 91%. The armature resistance is equal to 0.08Ω. The magnitude of armature current is nearly equal to

173 A.

190 A.

240 A.

127 A.

173 A.

190 A.

240 A.

127 A.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
When flux density is constant in a transformer, hysteresis loss varies as

f

f²

V²

V

f

f²

V²

V

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
In a DC machine the armature mmf is

stationary with respect to field poles.

rotating with respect to field poles.

stationary with respect to armature.

rotating with respect to field poles as well as armature.

stationary with respect to field poles.

rotating with respect to field poles.

stationary with respect to armature.

rotating with respect to field poles as well as armature.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines
Maximum allowable acidity level of power transformer insulating oil is generally taken as

0.5 mg of KOH / gm.

1 mg of KOH / gm.

0.3 mg of KOH / gm.

2 mg of KOH / gm.

0.5 mg of KOH / gm.

1 mg of KOH / gm.

0.3 mg of KOH / gm.

2 mg of KOH / gm.

ANSWER DOWNLOAD EXAMIANS APP

Electrical Machines

Electrical Machines In normal dc machines operating at full-load conditions, the most powerful electromagnet is

Electrical Machines A 500 V, 120 KW, 50 Hz, star connected synchronous motor operating at 0.8 power factor leading has full load efficiency of 91%. The armature resistance is equal to 0.08Ω. The magnitude of armature current is nearly equal to

Electrical Machines When flux density is constant in a transformer, hysteresis loss varies as

Electrical Machines In a DC machine the armature mmf is

Electrical Machines Maximum allowable acidity level of power transformer insulating oil is generally taken as

Electrical Machines
In normal dc machines operating at full-load conditions, the most powerful electromagnet is

Electrical Machines
A 500 V, 120 KW, 50 Hz, star connected synchronous motor operating at 0.8 power factor leading has full load efficiency of 91%. The armature resistance is equal to 0.08Ω. The magnitude of armature current is nearly equal to

Electrical Machines
When flux density is constant in a transformer, hysteresis loss varies as

Electrical Machines
In a DC machine the armature mmf is

Electrical Machines
Maximum allowable acidity level of power transformer insulating oil is generally taken as