Half Wave and Full Wave Rectifier - UNSOLVED PRACTICE SET

Q7. What is a rectifier? Why is rectification necessary?

Q8. Draw the circuit diagram of a half-wave rectifier and explain its working with input and output waveforms.

Q9. Draw the circuit diagram of a full-wave rectifier using a centre-tapped transformer and explain its working.

Q10. What is the ripple factor? Why is a lower ripple factor desirable in a rectifier circuit?

Q11. Compare half-wave and full-wave rectifiers in terms of:

(a) Number of diodes used

(b) Efficiency

(c) Ripple factor

(d) Peak inverse voltage

Q12. What is the role of a filter circuit in a rectifier? Name two types of filters.

Q13. Describe the construction and working of a half-wave rectifier with a circuit diagram. Draw the input and output waveforms and derive the expression for the average DC output voltage.

Q14. Describe the construction and working of a full-wave rectifier (both centre-tapped and bridge type) with circuit diagrams. Compare their advantages and disadvantages.

Q15. Derive the expressions for the ripple factor and efficiency of a half-wave rectifier. Explain why the full-wave rectifier has better performance in both respects.

Q16. A half-wave rectifier is connected to a 230 V, 50 Hz AC supply through a step-down transformer with turns ratio 10:1. The load resistance is 100 Ω.

(a) Calculate the peak voltage across the secondary winding.

(b) Calculate the average DC output voltage.

(c) Calculate the average DC load current.

(d) Calculate the DC power delivered to the load.

(e) Calculate the efficiency of the rectifier.

Q17. A full-wave bridge rectifier is connected to a 230 V, 50 Hz AC supply. The load resistance is 500 Ω. Assume ideal diodes.

(a) Calculate the peak output voltage.

(b) Calculate the average DC output voltage.

(c) Calculate the average DC load current.

(d) Calculate the ripple frequency.

(e) Calculate the PIV across each diode.

Q18. In your school electronics lab, a student is building rectifier circuits for a project.

(a) She builds a half-wave rectifier using a 12 V transformer and a silicon diode. She connects a 220 Ω load resistor. Calculate the average DC voltage and current across the load. Draw the expected output waveform.

(b) She then upgrades to a bridge rectifier using the same transformer and load. Calculate the new average DC voltage and current. Draw the output waveform and compare it with the half-wave output.

(c) The student adds a capacitor filter (1000 μF) across the output. Explain how this reduces ripple and calculate the approximate ripple voltage if the load current is 50 mA.

(d) A classmate suggests using a half-wave rectifier for a mobile phone charger because it uses fewer diodes. Discuss the disadvantages of this approach and why full-wave rectification is preferred.

(e) In India, the mains supply is 230 V, 50 Hz AC. Explain why the rectifier in your laptop adapter must handle this voltage and how the transformer, rectifier, and filter work together to provide smooth DC power.