Star Delta connections of Transformers

The ratio of the voltages of the primary and secondary transformers is equal to

• $\frac{Ns}{Np}$

• $\frac{Np}{Ns}$

• The current

• The power

The ratio of current equivalent to  $\frac{Vp}{Vs}$  is

•  $\frac{Is}{Ip}$  

• None of these

•  $\frac{Ip}{Is}$  

Each coil in a three phase transformer is set _________ degrees apart.

In a Delta system, how many currents are there?

Tick all of the following that apply to delta connection:

• VL = Vp

• VL = $\sqrt{3}$ x Vp

• IL = Ip

• IL = $\sqrt{3}$ x Ip

Delta connections are unbalanced loads that require a neutral.

• True

• False

Delta connections are balanced loads with equal currents on each line.

• True

• False

Tick all that apply for a star connection of 3 phase transformers.

• VL = Vp

• VL = $\sqrt{3}$ x Vp

• IL = Ip

• IL = $\sqrt{3}$ x Ip

In which configuration do we use Vp =  $\frac{VL}{\sqrt{3}}$  to find the phase voltage?

• star

• delta

In which configuration do we use Ip =  $\frac{IL}{\sqrt{3}}$  to find the phase current?

• star

• delta