Questions

1 A trio of generators are connected to 'a star':
A) If they have a terminal in common
B) If they have 2 terminals in common
C) If they feed a triphase system
D) If they feed a balanced triphase system

 

2 A trio of generators are connected to 'a triangle':
A) If they have a terminal in common
B) If they have 2 terminals in common
C) If they are connected so that they form the sides of a triangle
D) If they are connected in series

 

3 3 'triangle' generator are equivalent to 3 'star' generators even if they produce: :
A) A trio of tensions that are exactly the same as the star tensions resulting from the 3 'star' generators
B) A trio of tensions that are exactly the same as concatenated resulting from 3 'star' generators
C) A trio of balanced currents
D) A trio of symmetrical currents

 

4 A trio of impedences are connected in 'a star':
A) If they have a terminal in common
B) If they have 2 terminals in common
C) If they are in a series
D) If they are parallel

 

5 A load constituting 3 impedences is defined as balanced if:
A) The 3 impedences are null
B) The 3 impedences are only imaginary
C) The 3 impedences only have a real part
D) The 3 impedences are the same

 

6 A balanced load fed by a trio of symmetrical tensions, absorbs: :
A) A trio of balanced currents
B) A trio of symmetrical currents
C) A trio of spurious currents
D) A trio of null currents

 

7 In a symmetrical and balanced triphase system, tensions between the two star centres: :
A) Worth zero
B) Dipends on the tension values
C) Dipends on the current values
D) Coincides with the current output and impedence of each branch

 

8 In a symmetrical and balanced triphase system:
A) Each phase transfers a null power to the load
B) Each phase transfers 1/3 of total power to the load
C) Only the first phase transfers power to the load
D) Each phase transfers power proportional to the initial phase of the respective generators, to the load

 

9 The equivalent monophase system:
A) Allows the study of any triphase system
B) Allows the study of any symmetrical triphase system
C) Allows the study of any balanced triphase system
D) Allows the study of any symmetrical and balanced triphase system

 

10 Millman's theorm:
A) Applies only to symmetrical and balanced triphase systems
B) Applies only to symmetrical triphase systems
C) Applies only to balanced triphase systems
D) Applies to any triphase system