Regulated DC Power Supply MCQ

Regulated DC Power Supply MCQ

Q1. In an unregulated power supply, if load current increases, the output voltage ………..

Remains the same
Decreases
Increases
None of the above

Answer : 2

Q2. In an unregulated power supply, if input a.c. voltage increases, the output voltage …….

Increases
Decreases
Remains the same
None of the above

Answer : 1

Q3. A power supply which has voltage regulation of ……….. is unregulated power supply

0 %
5 %
10 %
8%

Answer : 3

Q4. Commercial power supplies have voltage regulation ………….

of 10%
of 15%
of 25%
within 1%

Answer : 4

Q5. An ideal regulated power supply is one which has voltage regulation of …………

0%
5%
10%
1%

Answer : 1

Regulated DC Power Supply MCQ

Q6. A Zener diode utilises ………… characteristic for voltage regulation

Forward
Reverse
Both forward and reverse
None of the above

Answer : 2

Q7. Zener diode can be used as …………

ac. voltage regulator only
dc. voltage regulator only
both d.c. and a.c. voltage regulator
none of the above

Answer : 3

Q8. A Zener diode is used as a …………… voltage regulating device

Shunt
Series
Series-shunt
None of the above

Answer : 1

Q9. As the junction temperature increases, the voltage breakdown point for Zener mechanism …………

Is increased
Is decreased
Remains the same
None of the above

Answer : 2

Q10. The rupture of co-valent bonds will occur when the electric field is ………….

100 V/cm
6 V/cm
1000 V/cm
More than 105 V/cm

Answer : 4

Regulated DC Power Supply MCQ

Q11. In a 15 V Zener diode , the breakdown mechanism will occur by ………….

Avalanche mechanism
Zener mechanism
Both Zener and avalanche mechanism
None of the above

Answer : 1

Q12. A Zener diode that has very narrow depletion layer will breakdown by ……… mechanism

Avalanche
Zener
Both avalanche and Zener
None of the above

Answer : 2

Q13. As the junction temperature increases, the voltage breakdown point for avalanche mechanism ………….

Remains the same
Decrease
Increases
None of the above

Answer : 3

Q14. Another name for Zener diode is ………… diode

Breakdown
Voltage
Power
Current

Answer : 1

Q15. Zener diode are generally made of ……….

Germanium
Silicon
Carbon
None of the above

Answer : 2

Regulated DC Power Supply MCQ

Q16. For increasing the voltage rating, zeners are connected in …………..

Parallel
Series-parallel
Series
None of the above

Answer : 3

Q17. In a Zener voltage regulator, the changes in load current produce changes in …………….

Zener current
Zener voltage
Zener voltage as well as Zener current
None of the above

Answer : 1

Q18. A Zener voltage regulator is used for …………… load currents

High
Very high
Moderate
Small

Answer : 4

Q19. A Zener voltage regulator will cease to act as a voltage regulator if Zener current becomes ……………

Less than load current
Zero
More than load current
None of the above

Answer : 2

Regulated DC Power Supply MCQ

Q20. If the doping level is increased, the breakdown voltage of the Zener …………..

Remains the same
Is increased
Is decreased
None of the above

Answer : 3

Q21. A 30 V Zener will have depletion layer width …………. that of 10 V Zener

More than
Less than
Equal to
None of the above

Answer : 1

Q22. The current in a Zener diode is limited by …………..

External resistance
Power dissipation
Both (1) and (2)
None of the above

Answer : 3

Q23. A 5 mA changes in Zener current produces a 50 mA change in Zener voltage. What is the Zener impedance?

1 Ω
1 Ω
100 Ω
10 Ω

Answer : 4

Q24. A certain regulator has a no-load voltage of 6 V and a full-load output of 5.82 V. What is the load regulation?

09%
87 %
72 %
None of the above

Answer : 1

Q25. What is true about the breakdown voltage in a Zener diode?

It decreases when load current increases
It destroys the diode
It equals current times the resistance
It is approximately constant

Answer : 4

Regulated DC Power Supply MCQ

Q26. Which of these is the best description for a Zener diode?

It is a diode
It is a constant current device
It is a constant-voltage device
It works in the forward region

Answer : 3

Q27. A Zener diode …………..

Is a battery
Acts like a battery in the breakdown region
Has a barrier potential of 1 V
Is forward biased

Answer : 2

Q28. The load voltage is approximately constant when a Zener diode is ……….

Forward biased
Unbiased
Reverse biased
Operating in the breakdown region

Answer : 4

Q29. In a loaded Zener regulator, which is the largest Zener current?

Series current
Zener current
Load current
None of the above

Answer : 1

Regulated DC Power Supply MCQ

Q30. If the load resistance decreases in a Zener regulator, then Zener current …………….

Decreases
Stays the same
Increases
None of the above

Answer : 1

Q31. If the input a.c. voltage to regulated or ordinary power supply increases by 5% what will be the approximate change in d.c. output voltage?

10%
20%
15%
5%

Answer : 4

Q32. If the load current drawn by unregulated power supply increases, the d.c. output voltage ………..

Increases
Decreases
Stays the same
None of the above

Answer : 2

Q33. If the load current drawn by unregulated power supply increases, the d.c. output voltage ………

Increases
Decreases
Stays the same
None of the above

Answer : 2

Q34. A power supply has a voltage regulation of 1%. If the no-load  voltage is 20 V, what is the full-load voltage?

8 V
7 V
6 V
2 V

Answer : 1

Regulated DC Power Supply MCQ

Q35. Two similar 15 V Zeners are connected in series. What is the regulated output voltage?

15 V
5 V
30 V
45 V

Answer : 3

Q36. A power supply can deliver a maximum rated current of 0.5 A at full-load output voltage of 20 V. What is the minimum load resistance that you can connect across the supply?

10 Ω
20 Ω
15 Ω
40 Ω

Answer : 4

Q37. In a regulated power supply, two similar 15 V zeners are connected in series. The input voltage is 45 V d.c. If each Zener has a maximum current rating of 300 mA, what should be the value of the series resistance?

10 Ω
50 Ω
25 Ω
40 Ω

Answer : 2

Q38. A Zener regulator …………… in the power supply

Increases the ripple
Decreases the ripple
Neither increases nor decreases the ripple
Data insufficient

Answer : 2

Q39. When load current is zero, the Zener current will be ………

Zero
Minimum
Maximum
None of the above

Answer : 3

Q40. The Zener current will be minimum when …………

Load current is maximum
Load current is minimum
Load current is zero
None of the above

Answer : 1

Regulated DC Power Supply MCQ

TO DOWNLOAD PDF CLICK HERE