Consider the following statements about a full-wave rectifier that uses two diodes and a centre-tap transformer:
(A) The p-sides of the two diodes are connected to the ends of the secondary of the transformer.
(B) The output is taken between the common point of the n-sides and the centre tap.
(C) Each diode rectifies the whole secondary voltage.
(D) Both diodes conduct together in each half-cycle.
Which of the above statements are incorrect?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (C) and (D) only
In this circuit the secondary has a tapping at its midpoint. Each diode works on one half of the secondary and conducts in its own half-cycle.
(A) The p-sides of the two diodes are connected to the ends of the secondary of the transformer. — Correct statement. The ends A and B of the secondary go to the p-sides of D1 and D2.
(B) The output is taken between the common point of the n-sides and the centre tap. — Correct statement. The n-sides are joined together, and the load is connected from this point to the centre tap.
(C) Each diode rectifies the whole secondary voltage. — Incorrect statement. Each diode lies between one end of the secondary and the centre tap. So it rectifies only half of the total secondary voltage.
(D) Both diodes conduct together in each half-cycle. — Incorrect statement. When A is positive, D1 conducts and D2 is reverse biased. In the next half-cycle the roles change, so the diodes conduct in turn.
NCERT (2026-27):
Application of Junction Diode as a Rectifier – “… Here the p-side of the two diodes are connected to the ends of the secondary of the transformer. …”
Application of Junction Diode as a Rectifier – “… The n-side of the diodes are connected together and the output is taken between this common point of diodes and the midpoint of the secondary of the transformer. …”
Application of Junction Diode as a Rectifier – “… the voltage rectified by each diode is only half the total secondary voltage. …”
Application of Junction Diode as a Rectifier – “… Each diode rectifies only for half the cycle, but the two do so for alternate cycles. …”