In step-up transfomer, the relation between number of turns in primary `(N_(p))` and number of turns in secondary `(N_(S))` coils is

Options

A. `N_(s)` is greater than `N_(p)`
B. `N_(p)` is greater than `N_(s)`
C. `N_(s)` is equal to `N_(p)`
D. `N_(p)=2N_(s)`

Answer

To find the relation between the number of turns in the primary coil (Np) and the number of turns in the secondary coil (Ns) of a step-up transformer, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Function of a Step-up Transformer**:
A step-up transformer is designed to increase the voltage from the primary coil to the secondary coil. This means that the voltage in the secondary coil (Vs) is greater than the voltage in the primary coil (Vp).

2. **Use the Transformer Voltage Relation**:
The relationship between the voltages and the number of turns in the coils of a transformer is given by the formula:
\[ \frac{Vp}{Vs} = \frac{Np}{Ns} \]
where:
- \(Vp\) = Voltage in the primary coil
- \(Vs\) = Voltage in the secondary coil
- \(Np\) = Number of turns in the primary coil
- \(Ns\) = Number of turns in the secondary coil

3. **Rearrange the Formula**:
Since we know that in a step-up transformer \(Vs > Vp\), we can rearrange the formula to express the relationship between the number of turns:
\[ \frac{Np}{Ns} = \frac{Vp}{Vs} \]
This implies that:
\[ Np < Ns \]

4. **Conclusion**:
Therefore, the relation between the number of turns in the primary and secondary coils in a step-up transformer is:
\[ Ns > Np \]

### Final Answer:
The number of turns in the secondary coil (Ns) is greater than the number of turns in the primary coil (Np).