Question

Compute the ripple factor of a single-phase full wave rectifier with load resistance R_L = 10 kΩ. Forward bias dynamic resistance of didoes used is 100 Ω. The rms voltage across secondary winding is 330 V.
1. 4.82
2. 1.21
3. 0.482
4. 0.812

Answer 1

Correct Answer - Option 3 : 0.482

Concept:

Ripple is the fluctuating AC component present in rectified DC output.

Ripple factor: It is the ratio of the RMS value of the ac component present in the rectified output to the average value of rectified output.

Ripple factor is given by (γ)=\(\sqrt {{{\left( {\frac{{{V_{rms}}}}{{{V_{avg}}}}} \right)}^2} - 1} \)

The quality of the DC waveform can be expressed in terms of the Ripple factor (or) Form factor.

For a full-wave rectifier,

V_rms =\(\;\frac{{{V_m}}}{{\sqrt 2 }}\) V

V_avg = \(\frac{{2{V_m}}}{\pi }\) V

Calculation:

γ =\(\sqrt {{{\left( {\frac{{\frac{{{V_m}}}{{\sqrt 2 }}}}{{\frac{{2{V_m}}}{\pi }}}} \right)}^2} - 1} \)

=\(\sqrt {{{\left( {\frac{\pi }{{2\sqrt 2 }}} \right)}^2} - 1} \)

= 0.481

Note: Ripple factor is independent of the secondary winding voltage