Diode as a half-wave and full-wave rectifier — practice questions

Question 1 · difficulty L1 · recall

A rectifier converts

• A. alternating voltage/current into a unidirectional output
• B. DC into AC
• C. light into sound only
• D. resistance into capacitance

Question 2 · difficulty L1 · understanding

A basic half-wave rectifier uses

• A. four diodes to pass no half-cycle
• B. one diode to pass one half-cycle
• C. a transistor only
• D. no nonlinear element

Question 3 · difficulty L2 · understanding

A full-wave rectifier uses

• A. only the positive half-cycle
• B. only every second input cycle
• C. both half-cycles of the AC input to produce the same output polarity
• D. no diodes

Question 4 · difficulty L2 · application

For a full-wave rectified sine wave supplied from frequency f, the ripple repetition frequency is

• A. f/2
• B. f
• C. 4f
• D. 2f

Question 5 · difficulty L3 · application

For an ideal half-wave rectifier with sinusoidal peak output Vm, the average output over a cycle is

• A. Vm/π
• B. 2Vm/π
• C. Vm/sqrt(2)
• D. zero

Question 6 · difficulty L3 · application

For an ideal full-wave rectified sine with peak Vm, the average output is

• A. Vm/π
• B. 2Vm/π
• C. Vm/2
• D. zero

Question 7 · difficulty L4 · analysis

Why is a filter capacitor often connected after a rectifier?

• A. To reverse the diode direction each half-cycle
• B. To increase AC ripple intentionally
• C. To reduce ripple by storing and releasing charge between voltage peaks
• D. To make the transformer work on DC

Question 8 · difficulty L4 · analysis

A bridge rectifier has the advantage that

• A. it uses no diodes
• B. its output remains AC with alternating polarity
• C. only one diode conducts in the whole bridge at any time
• D. it can provide full-wave rectification without a centre-tapped transformer secondary

Question 9 · difficulty L5 · analysis

If a half-wave rectifier diode is reversed, the output pulses

• A. switch to the opposite half-cycles
• B. remain exactly unchanged in polarity and timing
• C. disappear for all inputs
• D. double in frequency

Question 10 · difficulty L5 · analysis

Compared with a half-wave rectifier at the same input frequency, a full-wave rectifier is easier to smooth partly because

• A. it has no ripple at all before filtering
• B. its ripple pulses occur twice as often
• C. it needs no diodes
• D. its output alternates sign more strongly