A transformer has 230 volts applied to the primary and gives 4.6 V in the secondary. The secondary is connected to a load which draws a current of 5A. The current in the primary is

Options

A. 0.1
B. `1.0`
C. 10
D. 250

Answer

To find the current in the primary of the transformer, we can use the principle of conservation of energy, which states that the power in the primary side is equal to the power in the secondary side.

### Step-by-Step Solution:

1. **Identify the given values:**
- Voltage in the primary (Vp) = 230 V
- Voltage in the secondary (Vs) = 4.6 V
- Current in the secondary (Is) = 5 A

2. **Write the formula for power:**
The power in the primary (Pp) and the power in the secondary (Ps) can be expressed as:
\[ P_p = V_p \times I_p \]
\[ P_s = V_s \times I_s \]
Since power is conserved in the transformer, we have:
\[ P_p = P_s \]

3. **Set the two power equations equal to each other:**
\[ V_p \times I_p = V_s \times I_s \]

4. **Substitute the known values into the equation:**
\[ 230 \times I_p = 4.6 \times 5 \]

5. **Calculate the right side of the equation:**
\[ 4.6 \times 5 = 23 \]
So, the equation becomes:
\[ 230 \times I_p = 23 \]

6. **Solve for the primary current (Ip):**
\[ I_p = \frac{23}{230} \]

7. **Calculate the value:**
\[ I_p = 0.1 \, \text{A} \]

### Final Answer:
The current in the primary (Ip) is **0.1 A**.

---