Why does the National Grid use transformers to step-up the pd from power stations?
Because the higher the pd at which electrical energy is transmitted across the Grid, the smaller the energy wasted in the cables.
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Why are step-down transformer used?
To reduce the pd so that it is safe to be used by consumers.
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What is the equation used in relation to the pd across, and the number of turns on, the primary and secondary coils?
V_p overV_s = n_p over n_s (look up).
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In the equation in relation to the pd across, and the number of turns on, the primary and secondary coils, what is V_p?
The pd across the primary coil in volts (V).
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In the equation in relation to the pd across, and the number of turns on, the primary and secondary coils, what is V_s?
The pd across the secondary coil in volts (V).
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In the equation in relation to the pd across, and the number of turns on, the primary and secondary coils, what is n_p?
The number of turns on the primary coil.
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In the equation in relation to the pd across, and the number of turns on, the primary and secondary coils, what is n_s?
The number of turns on the secondary coil.
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How efficient are transformers and what is the equation for this?
Transformers are almost 100% efficient. 100% efficiency equation is V_p x I_p = V_s x I_s.
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In the equation for the efficiency of transformers, what is I_p?
The current in the primary in amperes (A).
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In the equation for the efficiency of transformers, what is I_s?
The current in the secondary in amperes (A).
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In a step-down transformer, what is n_s in relation to n_p?
For a step-down transformer, n_s is less than n_p.
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In a step-up transformer, what is n_s in relation to n_p?
For a step-up transformer, n_s is greater that n_p.
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Why is a transformer used to step-up the pd from a power station?
So that the electrical energy can be transmitted at a hight pd, reducing energy wasted in the cables.
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A transformer has 100 turns on the primary coil and 400 turns on the secondary coil. The pd across the primary coil is 2V. What is the pd across the secondary coil?
8V.
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**MAKE SURE THAT YOU CAN REARRANGE THE TRANSFORMER EQUATION**
**PRACTICE EQUATIONS IN RELATION TO TRANSFORMERS**
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**LOOK UP THE GRID SYSTEM**
**
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Other cards in this set
Card 2
Front
Why does the National Grid use transformers?
Back
To step-up the pd from power stations.
Card 3
Front
Why does the National Grid use transformers to step-up the pd from power stations?
Back
Card 4
Front
Why are step-down transformer used?
Back
Card 5
Front
What is the equation used in relation to the pd across, and the number of turns on, the primary and secondary coils?
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