Basic Electronics ECE

“The P-N Junction as a Diode”

1. How many junction/s do a diode consist?

• 0

• 1

• 2

• 3

2. The turn-on voltage of a Ge junction diode is nearly ______ volt.

• 0.7

• 0.3

• 1.0

• 0.1

3. Leakage current of a junction diode

• decreases with temperature

• is due to majority carriers

• depends on the method of its fabrication

• is in the range of mA or µA.

4. In the forward region of its characteristic a diode appears as

• an OFF switch

• a high resistance

• a capacitor

• an ON switch

5. What will be the output of the following circuit? (Assume 0.7V drop across the diode)

• 12V

• 12.7V

• 11.3V

• 0V

6. Bridge rectifier is an alternative for

• Full wave rectifier

• Peak rectifier

• Half wave rectifier

• None of the mentioned

7. A simple diode rectifier has ‘ripples’ in the output wave which makes it unsuitable as a DC source. To overcome this one can use

• A capacitor in series with a the load resistance

• A capacitor in parallel to the load resistance

• Both of the mentioned situations will work

• None of the mentioned situations will work

8. Efficiency of a half wave

rectifier is

• 50%

• 60%

• 40.6%

• 46%

9. The inductor filter gives a smooth output because_________

• It offers infinite resistance to ac components

• It offers infinite resistance to dc components

• Pulsating dc signal is allowed

• The ac signal is amplified

10. The output of a rectifier is pulsating because_________

• It has a pulse variations

• It gives a dc output

• It contains both dc and ac components

• It gives only ac components