Grade 10 - Diodes and Rectification Quiz

Draw the circuit symbol for a diode and label the anode and cathode. (Select the correct diagram)

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What is the difference between forward bias and reverse bias in a diode?

• Forward bias blocks current; reverse bias allows it

• Forward bias allows current after ~0.7V; reverse bias blocks current

• Both allow current equally

• Forward bias only works with LEDs

You have a 9 V supply, a red LED (VF = 2 V) and you want 15 mA of current. What resistor value should you use?

• 330 Ω

• 390 Ω

• 470 Ω

• 680 Ω

What happens to the LED if you increase the resistor value in series?

• Gets brighter

• No change

• Gets dimmer

• Burns out

Why do we always use a resistor in series with an LED? (Select TWO)

• To limit current and protect LED

• To control brightness

• To store charge for LED

• To reverse polarity

In a half-wave rectifier, what happens during the negative half of the AC cycle?

• The diode conducts more

• The diode is reverse biased and no current flows

• The output voltage doubles

• Both positive and negative voltage appear at the output

Why is a full-wave bridge rectifier more efficient than a half-wave rectifier?

• It uses fewer diodes

• It uses both halves of the AC cycle

• It produces AC from DC

• It requires no smoothing

In a full-wave bridge rectifier, which diodes conduct during the positive half-cycle?

• D3 & D4

• D1 & D2

• D2 & D3

• D1 & D4

In a full-wave bridge rectifier, which diodes conduct during the negative half-cycle?

• D1 & D2

• D2 & D3

• D3 & D4

• D1 & D4

Which waveform best represents a full-wave rectifier output?

• Positive peaks with gaps (only half of the sine wave)

• Positive peaks for both halves of the sine wave

• Pure sine wave

• Flat DC line