The purpose of this experiment was to study transformers and power transmission by applying AC signals to primary coils and measuring induced voltages/currents in secondary coils. Two transformers (step-down: Np/Ns=0, step-up: Np/Ns=0/0) were tested. Using an AC signal generator (000 Hz), voltages (Vp) were applied to the primary coil. Digital multimeters measured secondary voltages (Vs) and currents (Ip, Is). Power input (Pp) and output (Ps) were calculated, and efficiency (Ps/Pp ×000%) was determined. Results showed voltage ratios matched turns ratios (e.g., Vs≈0.0Vp for Np/Ns=0), but efficiencies ranged 00-00%, confirming real-world losses.