**TRANSISTOR TUNED AMPLIFIERS Questions :-**

**1. A tuned amplifier uses ……………. load**

- Resistive
- Capacitive
- LC tank
- Inductive

Ans : 3

**2. A tuned amplifier is generally operated in ……………. operation**

- Class A
- Class C
- Class B
- None of the above

Ans : 2

**3. A tuned amplifier is used in …………… applications**

- Radio frequency
- Low frequency
- Audio frequency
- None of the above

Ans : 1

**4. Frequencies above …………… kHz are called radio frequencies**

- 2
- 10
- 50
- 200

Ans : 4

**5. At series or parallel resonance, the circuit power factor is …………..**

- 0
- 5
- 1
- 8

Ans : 3

**6. The voltage gain of a tuned amplifier is ……………. at resonant frequency**

Minimum

Maximum

Half-way between maximum and minimum

Zero

Ans : 2

**7. At parallel resonance, the line current is ……………….**

Minimum

Maximum

Quite large

None of the above

Ans : 1

**8. At series resonance, the circuit offers …………….. impedance**

Zero

Maximum

Minimum

None of the above

Ans : 3

**9. A resonant circuit contains ……………… elements**

R and L only

R and C only

Only R

L and C

Ans : 4

**10. At series or parallel resonance, the circuit behaves as a …………….. load**

Capacitive

Resistive

Inductive

None of the above

Ans : 2

**11. At series resonance, voltage across L is ………………. voltage across C**

Equal to but opposite in phase to

Equal to but in phase with

Greater than but in phase with

Less than but in phase with

Ans : 1

**12. When either L or C is increased, the resonant frequency of LC circuit ……………**

Remains the same

Increases

Decreases

Insufficient data

Ans : 3

**13. At parallel resonance, the net reactive component circuit current is …………**

Capacitive

Zero

Inductive

None of the above

Ans : 2

**14. In parallel resonance, the circuit impedance is …………..**

C/LR

R/LC

CR/L

L/CR

Ans : 4

**15. In a parallel LC circuit, if the input signal frequency is increased above resonant frequency then …………………..**

XL increases and XC decreases

XL decreases and XC increases

Both XL and XC increase

Both XL and XC decrease

Ans : 1

**16. The Q of an LC circuit is given by ………………….**

2pfr x R

R / 2pfrL

2pfrL / R

R2/2pfrL

Ans : 3

**17. If Q of an LC circuit increases, then bandwidth …………………**

Increases

Decreases

Remains the same

Insufficient data

Ans : 2

**18. At series resonance, the net reactive component of circuit current is ……………….**

Zero

Inductive

Capacitive

None of the above

Ans : 1

**19. The dimensions of L/CR are that of …………….**

Farad

Henry

Ohm

None of the above

Ans : 3

**20. If L/C ratio of a parallel LC circuit is increased, the Q of the circuit ……………..**

Is decreased

Is increased

Remains the same

None of the above

Ans : 2

**21. At series resonance, the phase angle between applied voltage and circuit is ………..**

90o

180o

0o

None of the above

Ans : 3

**22. At parallel resonance, the ratio L/C is …………….**

Very large

Zero

Small

None of the above

Ans : 1

**23. If the resistance of a tuned circuit is increased, the Q of the circuit ………….**

Is increased

Is decreased

Remains the same

None of the above

Ans : 2

**24. The Q of a tuned circuit refers to the property of …………..**

Sensitivity

Fidelity

Selectivity

None of the above

Ans : 3

**25. At parallel resonance, the phase angle between the applied voltage and circuit current is …………….**

90o

180o

0o

None of the above

Ans : 3

**26. In a parallel LC circuit, if the signal frequency is decreased below the resonant frequency, then ……………**

XL decreases and XC increases

XL increases and XC decreases

Line current becomes minimum

None of the above

Ans : 1

**27. In series resonance, there is ………………**

Voltage amplification

Current amplification

Both voltage and current amplification

None of the above

Ans : 1

**28. The Q of a tuned amplifier is generally …………….**

Less than 5

Less than 10

More than 10

None of the above

Ans : 3

**29. The Q of a tuned amplifier is 50. If the resonant frequency for the amplifier is 1000kHZ, then bandwidth is …………**

10kHz

40 kHz

30 kHz

20 kHz

Ans : 4

**30. In the above question, what are the values of cut-off frequencies?**

140 kHz , 60 kHz

1020 kHz , 980 kHz

1030 kHz , 970 kHz

None of the above

Ans : 2

**31. For frequencies above the resonant frequency, a parallel LC circuit behaves as a ……………. load**

Capacitive

Resistive

Inductive

None of the above

Ans : 1

**32. In parallel resonance, there is …………**

Both voltage and current amplification

Voltage amplifications

Current amplification

None of the above

Ans : 3

**33. For frequencies below resonant frequency, a series LC circuit behaves as a ………… load**

Resistive

Capacitive

Inductive

None of the above

Ans : 2

**34. If a high degree of selectivity is desired, then double-tuned circuit should have …………. coupling**

Loose

Tight

Critical

None of the above

Ans : 1

**35. In the double tuned circuit, if the mutual inductance between the two tuned circuits is decreased, the level of resonance curve ………..**

Remains the same

Is lowered

Is raised

None of the above

Ans : 3

**36. For frequencies above the resonant frequency , a series LC circuit behaves as a ………….. load**

Resistive

Inductive

Capacitive

None of the above

Ans : 2

**37. Double tuned circuits are used in ……………. stages of a radio receiver**

IF

Audio

Output

None of the above

Ans : 1

**38. A class C amplifier always drives ………. load**

A pure resistive

A pure inductive

A pure capacitive

A resonant tank

Ans : 4

**39. Tuned class C amplifiers are used for RF signals of ………………**

Low power

High power

Very high power

None of the above

Ans : 4

**40. For frequencies below the resonant frequency , a parallel LC circuit behaves as a …………… load**

- Inductive
- Resistive
- Capacitive
- None of the above

Ans : 1