Correct Answer - Option 2 : 1250 V
Concept:
Transformation ratio: It is defined as the ratio of the secondary voltage to the primary voltage. It is denoted by 'K'.
\(K = \frac{{{N_2}}}{{{N_1}}} = \frac{{{V_2}}}{{{V_1}}} = \frac{{{I_1}}}{{{I_2}}}\) ----- (1)
Turns ratio or Voltage ratio: It is defined as the ratio of primary winding turns to secondary winding turns. It is denoted by 'a'.
\(a = \frac{{{1}}}{{{K}}} = \frac{{{N_1}}}{{{N_2}}} = \frac{{{V_1}}}{{{V_2}}} = \frac{{{I_2}}}{{{I_1}}}\) ----- (2)
N1 = primary winding turns
N2 = secondary winding turns
V1 = primary winding voltage
V2 = secondary winding voltage
I1 = current through the primary winding
I2 = current through the secondary winding
Calculation:
Given:
N1 = 400, N2 = 1000, V1 = 500, V2 =?
from eq (2), we can write
\(\frac{{{V_1}}}{{{V_2}}} = \frac{{{N_1}}}{{{N_2}}}\)
\(\frac{{500}}{{{V_2}}} = \frac{{400}}{{1000}}\)
V2 = 1250 V