Transformer Practice Exam

[Vysakh9292]

A certain transformer has a turns ratio of 1 and a 0.85 coefficient of coupling. When 2 V ac is applied to the primary, the secondary voltage is

A. 1.7 V
B. 0.85 V
C. 1 V
D. 0 V

[Vysakh9292]

The primary coil of a transformer is connected to a 60 V ac source. The secondary coil is connected to a 330 load. The turns ratio is 3:1. What is the secondary voltage?

A. 2 V
B. 20 V
C. 180 V
D. 18 V

[Vysakh9292]

The primary winding of a power transformer should always be

A. open
B. shorted
C. switched
D. fused

[Vysakh9292]

When a 200 load resistor is connected across the secondary winding of a transformer with a turns ratio of 4, the source "sees" a reflective load of

A. 50
B. 12.5
C. 800
D. 0

[Vysakh9292]

When a 6 V battery is connected across the primary of a transformer with a turns ratio of 8, the secondary voltage is

A. 0 V
B. 6 V
C. 48 V
D. 0.75 V

[Vysakh9292]

What is the coefficient of coupling for a transformer in which 4% of the total flux generated in the primary does not pass through the secondary?

A. 0.4
B. 4
C. 9.6
D. 0.96

[Vysakh9292]

A transformer has a 1:6 turns ratio and a secondary coil load resistance of 470 . The load resistance as seen by the source is

A. 1.3
B. 7.8
C. 78
D. 13

[Vysakh9292]

When the speed at which a conductor is moved through a magnetic field is increased, the induced voltage

A. increases
B. decreases
C. remains constant
D. reaches zero

[Vysakh9292]

For a given wirewound core, an increase in current through the coil

A. reverses the flux lines
B. decreases the flux density
C. increases the flux density
D. causes no change in flux density

[rsgordineer]

What kVA rating is required for a transformer that must handle a maximum load current of 8 A with a secondary voltage of 2 kV?

A. 4 kVA
B. 0.25 kVA
C. 16 kVA
D. 8 kVA

8A multiplied by 2kV = 16kVA.