Rectifiers — Half wave, full wave
Semiconductor
11
JEE Qs
8%
Hard
75
min
Master the circuit diagrams, input/output waveforms, and the calculation of average/RMS values and PIV for both half-wave and full-wave rectifiers.
🧮 Key Formulas
✅ Key Points for JEE
- 1A rectifier converts alternating current (AC) into pulsating direct current (DC) using semiconductor diodes which allow current flow in only one direction.
- 2Half-wave rectifiers (HWR) pass only one half-cycle of the input AC, while full-wave rectifiers (FWR) utilize both half-cycles, leading to higher efficiency and lower ripple.
- 3The output frequency of a HWR is equal to the input AC frequency, whereas for a FWR, it is twice the input AC frequency.
- 4Full-wave rectifiers (both center-tap and bridge) have significantly higher DC output voltage, lower ripple factor, and better rectification efficiency compared to half-wave rectifiers.
- 5Peak Inverse Voltage (PIV) is the maximum voltage a diode must withstand in reverse bias and is critical for selecting appropriate diodes for the rectifier circuit.
⚠️ Common Mistakes
- ✕Confusing the average (DC) and RMS values of current and voltage for half-wave vs. full-wave rectifiers.
- ✕Incorrectly calculating the Peak Inverse Voltage (PIV), especially for the center-tap full-wave rectifier where it is 2V_m.
- ✕Not accounting for the 0.7V (or specified V_F) forward voltage drop across each silicon diode when calculating output voltage/current in non-ideal scenarios.
📝 Practice Questions
See allQ27.Consider the following statements: A. The junction area of solar cell is made very narrow compared to a photo diode. B. Solar cells are not connected with any external bias. C. LED is made of lightly doped p-n junction. D. Increase of forward current results in continuous increase of LED light intensity. E. LEDs have to be connected in forward bias for emission of light. Choose the correct answer from the options given below: (1) B, E Only (2) B, D, E Only (3) A, C Only (4) A, C, E Only
Q43.Which of the following circuits has the same outpur as that of the given circuit? (1) (2) (3) (4)
Q33.Which of the following circuits represents a forward biased diode? Choose the correct answer from the options given below : (1) (A) and (D) only (2) (B), (D) and (E) only (3) (C) and (E) only (4) (B), (C) and (E) only
Q26. A B Y 0 0 1 0 1 1 1 0 0 1 1 1 To obtain the given truth table, following logic gate should be placed at G: 2025 (22 Jan Shift 2) JEE Main Previous Year Paper (1) OR Gate (2) AND Gate (3) NOR Gate (4) NAND Gate
Q28.The output of the circuit is low (zero) for : (A) X = 0, Y = 0 (B) X = 0, Y = 1 (C) X = 1, Y = 0 (D) X = 1, Y = 1 Choose the correct answer from the options given below : (1) (B), (C) and (D) only (2) (A), (B) and (C) only (3) (A), (C) and (D) only (4) (A), (B) and (D) only
Q45. In the circuit shown here, assuming threshold voltage of diode is negligibly small, then voltage VAB is correctly represented by : (1) VAB would be zero at all times (2) (3) (4)
NCERT Chapters
- Class 12 Physics Ch 14: Semiconductor Electronics: Materials, Devices and Simple Circuits