Transformers and the national grid

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Question 7
Medium

An ideal step-up transformer at a power station links the generators to the high-voltage transmission lines of the national grid. The alternating current in the primary coil is 2.4 kA2.4\text{ kA}2.4 kA and the alternating current in the secondary coil is 80 A.

What are the ratios of the primary-to-secondary voltage, VpVs\displaystyle \frac{V_p}{V_s}Vs​Vp​​, and the primary-to-secondary turns, NpNs\displaystyle \frac{N_p}{N_s}Ns​Np​​, for this transformer?

VpVs=30\frac{V_p}{V_s} = 30Vs​Vp​​=30 and NpNs=30\frac{N_p}{N_s} = 30Ns​Np​​=30

VpVs=130\frac{V_p}{V_s} = \frac{1}{30}Vs​Vp​​=301​ and NpNs=30\frac{N_p}{N_s} = 30Ns​Np​​=30

VpVs=130\frac{V_p}{V_s} = \frac{1}{30}Vs​Vp​​=301​ and NpNs=130\frac{N_p}{N_s} = \frac{1}{30}Ns​Np​​=301​

VpVs=30\frac{V_p}{V_s} = 30Vs​Vp​​=30 and NpNs=130\frac{N_p}{N_s} = \frac{1}{30}Ns​Np​​=301​

Transformers and the national grid Questions

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