The primary voltage of a transformer is 200 volts and the secondary voltage is 50 volts. If the number of turns in the secondary winding is 100, the number of turns in the primary is _________

Correct option is C

​$$\text{Given data,} \\\text{Primary Voltage } (V_1) = 200\,\text{V} \\\text{Secondary Voltage } (V_2) = 50\,\text{V} \\\text{Secondary turns } (N_2) = 100 \\\text{Primary turns } (N_1) = ? \\\\\therefore \boxed{\frac{V_1}{V_2} = \frac{N_1}{N_2} = \frac{I_2}{I_1}} \\\\\frac{V_1}{V_2} = \frac{N_1}{N_2} \\\frac{200}{50} = \frac{N_1}{100} \\N_1 = \frac{200 \times 100}{50} = 200 \times 2 = 400 \, \text{turns.}$$​​