The primary winding of a transformer has `100` turns and its secondary winding has `200` turns. The primary is connected to an ac supply of `120V` and the current flowing in it is `10A`. The voltage and the current in the secondary are

Options

A. 240 V, 5 A
B. 240 V, 10 A
C. 60 V, 20 A
D. 120V, 20 A

Answer

To solve the problem, we need to find the voltage and current in the secondary winding of a transformer given the specifications of the primary winding. Let's break it down step by step.

### Step 1: Identify the given values
- Number of turns in the primary winding (Np) = 100 turns
- Number of turns in the secondary winding (Ns) = 200 turns
- Primary voltage (Vp) = 120 V
- Primary current (Ip) = 10 A

### Step 2: Use the transformer turns ratio to find the secondary voltage (Vs)
The relationship between the primary and secondary voltages and the number of turns in the transformer is given by the formula:

\[ \frac{V_p}{V_s} = \frac{N_p}{N_s} \]

From this, we can express the secondary voltage (Vs) as:

\[ V_s = V_p \times \frac{N_s}{N_p} \]

Substituting the known values:

\[ V_s = 120 \, \text{V} \times \frac{200}{100} \]

Calculating this gives:

\[ V_s = 120 \, \text{V} \times 2 = 240 \, \text{V} \]

### Step 3: Calculate the secondary current (Is)
Assuming the transformer is ideal (100% efficiency), the power input to the primary side equals the power output from the secondary side. Thus:

\[ V_p \times I_p = V_s \times I_s \]

Rearranging this to find the secondary current (Is):

\[ I_s = \frac{V_p \times I_p}{V_s} \]

Substituting the known values:

\[ I_s = \frac{120 \, \text{V} \times 10 \, \text{A}}{240 \, \text{V}} \]

Calculating this gives:

\[ I_s = \frac{1200}{240} = 5 \, \text{A} \]

### Final Results
- The secondary voltage (Vs) is **240 V**.
- The secondary current (Is) is **5 A**.

### Summary
The required secondary voltage and current are:
- **Voltage (Vs)** = 240 V
- **Current (Is)** = 5 A

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