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An 11000/440 ...

Question

An 11000/440 V, 50 Hz, 3-phase transformer is delta connected on the hv side and the lv windings are star connected. There should be 12 V per turn and the flux density is not to exceed $1.2 W b / m^{2}$ .
The net cross sectional area of core in $c m^{2}$ is _______.
450.45

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Solution

The correct option is A 450.45
$Voltage per turn = 12 V$

$\Rightarrow \frac{V_{p h_{2}}}{N_{2}} = 12$

Also, $\frac{V_{p h_{2}}}{N_{2}} = 4.44 \times B_{m} \times A \times f$
$\Rightarrow 12 = 4.44 \times 1.2 \times 50 \times A$

$\Rightarrow A r e a = 450.45 c m^{2}$

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