At grid sub-stations the voltage is stepped up to reduce loss of

Options

A. current
B. electrical energy
C. Power
D. resistance

Answer

To solve the question, we need to understand why the voltage is stepped up at grid substations. The main goal of stepping up the voltage is to reduce power loss during transmission. Here’s a step-by-step explanation:

### Step-by-Step Solution:

1. **Understanding Power Transmission**: When electrical power is transmitted over long distances, it encounters resistance in the transmission lines. This resistance causes power loss in the form of heat.

2. **Power Loss Formula**: The power loss (P_loss) in a transmission line can be calculated using the formula:
\[ P_{\text{loss}} = I^2 R \]
where \(I\) is the current flowing through the line and \(R\) is the resistance of the line.

3. **Effect of Voltage on Current**: According to Ohm's Law, the relationship between voltage (V), current (I), and resistance (R) is given by:
\[ V = I \times R \]
Rearranging this gives us:
\[ I = \frac{V}{R} \]
This means that if the voltage is increased, the current will decrease for a constant power level.

4. **Stepping Up Voltage**: By stepping up the voltage at substations, the current in the transmission lines is reduced. Since power loss is proportional to the square of the current (\(I^2\)), reducing the current significantly reduces the power loss.

5. **Conclusion**: Therefore, the main reason for stepping up the voltage at grid substations is to reduce electrical power loss during transmission.

### Final Answer:
At grid substations, the voltage is stepped up to reduce loss of **electrical power**.

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