A transformer consisting of 300 turns in the primary and 150 turns in the secondary gives output power of 2.2 kW. If the current in the secondary coil is 10A, then the input voltage and current in the primary coil are :

Alternating Current PYQ — JEE Main 2019 · 10 Apr · Shift 1 · Q48 with Solution

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Correct answer: C

Given data
- Number of turns in primary: $N_p = 300$
- Number of turns in secondary: $N_s = 150$
- Output power: $P_{out} = 2.2\,\text{kW} = 2200\,\text{W}$
- Secondary current: $I_s = 10\,\text{A}$
Find the secondary voltage Using output power, $P_{out} = V_s I_s$ $2200 = V_s \times 10$ $V_s = 220\,\text{V}$
Use transformer turns ratio For an ideal transformer, $\frac{V_p}{V_s} = \frac{N_p}{N_s}$ Substituting values, $\frac{V_p}{220} = \frac{300}{150} = 2$ $V_p = 440\,\text{V}$
Find primary current For an ideal transformer, input power equals output power: $P_{in} = P_{out} = 2200\,\text{W}$ So, $P_{in} = V_p I_p$ $2200 = 440 \times I_p$ $I_p = 5\,\text{A}$
Check with options
- A: $220\,\text{V}$ and $20\,\text{A}$ ❌
- B: $220\,\text{V}$ and $10\,\text{A}$ ❌
- C: $440\,\text{V}$ and $5\,\text{A}$ ✅
- D: $440\,\text{V}$ and $20\,\text{A}$ ❌

Therefore, the correct answer is Option C.