Let the voltage in primary coil of transformer be V_p . Thus voltage in secondary coil of transformer V_s = 100 V_p Using P_p = P_s \ herefore V_p I_p=V_s I_s Or V_p I_p = (100 V_p) I_s \\implies I_s = \\dfrac{I_p}{100} Thus current must be reduced by a factor of 100 .