Statement-1 : A step up transformer can also be used as a step down transformer.

Statement-2 : This is because `E_s/E_P`=`n_s/n_P`

Answer

To solve the question, we need to analyze both statements provided:

**Statement 1:** A step-up transformer can also be used as a step-down transformer.
**Statement 2:** This is because \( \frac{E_s}{E_P} = \frac{n_s}{n_P} \).

### Step-by-Step Solution:

1. **Understanding Transformer Functionality:**
- A transformer operates on the principle of electromagnetic induction and consists of two coils: the primary coil and the secondary coil.
- The primary coil receives input voltage, while the secondary coil delivers output voltage.

2. **Step-Up Transformer:**
- In a step-up transformer, the number of turns in the secondary coil (\( n_s \)) is greater than that in the primary coil (\( n_p \)).
- This results in an increase in voltage from primary to secondary, which can be expressed as:
\[ \frac{E_s}{E_P} = \frac{n_s}{n_P} > 1 \]
- Here, \( E_s \) is the secondary voltage and \( E_P \) is the primary voltage.

3. **Reversing the Transformer:**
- If we reverse the roles of the coils, making the secondary coil act as the primary coil and vice versa, the transformer can still function.
- In this case, the original secondary coil (now acting as the primary) will have a higher number of turns than the original primary coil (now acting as the secondary).

4. **Step-Down Transformer:**
- When the transformer is used in reverse, the voltage will decrease, making it function as a step-down transformer.
- The relationship now becomes:
\[ \frac{E_P}{E_s} = \frac{n_P}{n_s} < 1 \]
- This indicates that the voltage across the new primary (originally secondary) is less than the voltage applied to it.

5. **Conclusion:**
- Both statements are correct. A step-up transformer can indeed be used as a step-down transformer when the roles of the coils are reversed.
- The relationship \( \frac{E_s}{E_P} = \frac{n_s}{n_P} \) explains the voltage transformation based on the turns ratio.

### Final Answer:
Both Statement 1 and Statement 2 are correct.

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