Step up Transformer:
A step-up transformer is a type of transformer that increases the voltage from the primary winding to the secondary winding. It consists of two coils, a primary coil with fewer turns and a secondary coil with more turns. The primary coil is connected to the input voltage source, while the secondary coil is connected to the load.

Diagram:
Here is a well-labelled diagram of a step-up transformer:

![Step Up Transformer Diagram](

https://www.edurev.in/api/v2/image/60cfe312e6b33c6a5cbbf4b8) https://www.edurev.in/api/v2/image/60cfe312e6b33c6a5cbbf4b8)

Ratio of Secondary to Primary Voltage:
The ratio of secondary to primary voltage in a transformer can be determined by the ratio of the number of turns in the secondary coil to the number of turns in the primary coil. This can be expressed mathematically as:

\(\frac{V_s}{V_p} = \frac{N_s}{N_p}\)

Where:
\(V_s\) = Secondary voltage
\(V_p\) = Primary voltage
\(N_s\) = Number of turns in the secondary coil
\(N_p\) = Number of turns in the primary coil

Ratio of Secondary to Primary Current:
The ratio of secondary to primary current in a transformer is inversely proportional to the ratio of the number of turns in the secondary coil to the number of turns in the primary coil. This can be expressed mathematically as:

\(\frac{I_s}{I_p} = \frac{N_p}{N_s}\)

Where:
\(I_s\) = Secondary current
\(I_p\) = Primary current
\(N_s\) = Number of turns in the secondary coil
\(N_p\) = Number of turns in the primary coil

Example:
Given:
Primary voltage (\(V_p\)) = 2200 V
Number of turns in primary coil (\(N_p\)) = 3000
Secondary voltage (\(V_s\)) = 220 V

To find:
Number of turns in secondary coil (\(N_s\))

Using the formula for the ratio of secondary to primary voltage:

\(\frac{V_s}{V_p} = \frac{N_s}{N_p}\)

Substituting the given values:

\(\frac{220}{2200} = \frac{N_s}{3000}\)

Simplifying the equation:

\(\frac{1}{10} = \frac{N_s}{3000}\)

Cross-multiplying:

\(N_s = \frac{1}{10} \times 3000\)

\(N_s = 300\)

Therefore, the number of turns in the secondary coil (\(N_s\)) is 300.

Explanation:
In a step-down transformer, the secondary voltage is lower than the primary voltage. This allows the transformer to "step down" the voltage from the power transmission line to a level suitable for use in homes and businesses. The number of turns in the secondary coil is less than the number of turns in the primary coil, resulting in a lower voltage output.

In the given example, the primary voltage is 2200 V and the number of turns in the primary coil is 3000. The desired output voltage is 220 V. By rearranging the formula for the ratio of secondary to primary voltage, we can solve for