Which of the following statements is correct for a bridge rectifier?

The correct statement for a bridge rectifier is: 3) The transformer utilization factor (TUF) of a bridge rectifier is higher than that of a center-tapped rectifier.

Explanation:

• Transformer Utilization Factor (TUF): TUF is a measure of how effectively the transformer is utilized in a rectifier circuit. A higher TUF indicates better utilization.

  • For a bridge rectifier, the ideal TUF is approximately 0.812.

  • For a center-tapped full-wave rectifier, the ideal TUF is approximately 0.693. Therefore, the bridge rectifier has a higher TUF.

Let's look at the other options:

• 1) The transformer utilization factor (TUF) is the same for both bridge and center-tapped rectifiers.

  • Incorrect, as explained above.

• 2) A bridge rectifier has twice the PIV of a center-tapped rectifier.

  • Incorrect. The Peak Inverse Voltage (PIV) for each diode in a bridge rectifier is Vm​ (where Vm​ is the peak secondary voltage across the entire transformer winding). For a center-tapped full-wave rectifier, the PIV for each diode is 2Vm,half​ (where Vm,half​ is the peak voltage across half the secondary winding). If Vm​ represents the peak output voltage, then the PIV for bridge is Vm​, and for center-tapped is 2Vm​. This means the bridge rectifier's diodes experience half the PIV stress compared to the diodes in a center-tapped rectifier for the same output voltage.

• 4) A bridge rectifier has a lower ripple factor than a center-tapped rectifier.

  • Incorrect. Both bridge rectifiers and center-tapped full-wave rectifiers are full-wave rectifiers. Assuming an unfiltered output, they both produce a ripple frequency twice the input frequency and have the same theoretical ripple factor (approximately 0.482 or 48.2%).