For a step down transformer

Options

A. `N_p gt N_s`
B. `N_p lt N_s`
C. `N_p = N_s`
D. `N_p gt= N_s`

Explanation

### Step-by-Step Solution:

1. **Understanding the Transformer**: A step-down transformer is a device that converts high voltage electricity into lower voltage electricity. It has two coils: the primary coil (input) and the secondary coil (output).

2. **Identifying the Turns**: In a step-down transformer, the number of turns in the primary coil (N1) is greater than the number of turns in the secondary coil (N2). This is a key characteristic of step-down transformers.

3. **Voltage Relation**: The relationship between the primary voltage (V1) and the secondary voltage (V2) in a transformer is given by the formula:
\[ \frac{V2}{V1} = \frac{N2}{N1} \]
For a step-down transformer, since N2 < N1, it follows that V2 < V1.

4. **Conclusion**: Therefore, in a step-down transformer, the voltage in the secondary coil (V2) is less than the voltage in the primary coil (V1), and the number of turns in the secondary coil (N2) is less than the number of turns in the primary coil (N1).

5. **Final Answer**: The correct relationship for a step-down transformer is that the number of turns in the secondary (N2) is less than the number of turns in the primary (N1).