UNIT _ III MCQ Ans : C Ans : C Ans : C
Ans : A Ans : B Multiple Choice Questions and Answers on Transistor Tuned Amplifiers Q1. A tuned amplifier uses. load 1. Resistive 2. Capacitive 3. LC tank 4. Inductive Q2. A tuned amplifier is generally operated in. operation 1. Class A 2. Class C 3. Class B Q3. A tuned amplifier is used in applications 1. Radio frequency 2. Low frequency 3. Audio frequency
Q4. Frequencies above khz are called radio frequencies 1. 2 2. 10 3. 50 4. 200 Q5. At series or parallel resonance, the circuit power factor is.. 1. 0 2. 5 3. 1 4. 8 Q6. The voltage gain of a tuned amplifier is. at resonant frequency 1. Minimum 2. Maximum 3. Half-way between maximum and minimum 4. Zero Q7. At parallel resonance, the line current is. 1. Minimum 2. Maximum 3. Quite large Q8. At series resonance, the circuit offers.. impedance 1. Zero 2. Maximum 3. Minimum Q9. A resonant circuit contains elements 1. R and L only 2. R and C only 3. Only R 4. L and C
Q10. At series or parallel resonance, the circuit behaves as a.. load 1. Capacitive 2. Resistive 3. Inductive Q11. At series resonance, voltage across L is. voltage across C 1. Equal to but opposite in phase to 2. Equal to but in phase with 3. Greater than but in phase with 4. Less than but in phase with Q12. When either L or C is increased, the resonant frequency of LC circuit 1. Remains the same 2. Increases 3. Decreases 4. Insufficient data Q13. At parallel resonance, the net reactive component circuit current is 1. Capacitive 2. Zero 3. Inductive Q14. In parallel resonance, the circuit impedance is.. 1. C/LR 2. R/LC 3. CR/L 4. L/CR Q15. In a parallel LC circuit, if the input signal frequency is increased above resonant frequency then.. 1. X L increases and X C decreases 2. X L decreases and X C increases 3. Both X L and X C increase 4. Both X L and X C decrease
Q16. The Q of an LC circuit is given by. 1. 2πf r x R 2. R / 2πf r L 3. 2πf r L / R 4. R 2 /2πf r L Q17. If Q of an LC circuit increases, then bandwidth 1. Increases 2. Decreases 3. Remains the same 4. Insufficient data Q18. At series resonance, the net reactive component of circuit current is. 1. Zero 2. Inductive 3. Capacitive Q19. The dimensions of L/CR are that of. 1. Farad 2. Henry 3. Ohm Q20. If L/C ratio of a parallel LC circuit is increased, the Q of the circuit.. 1. Is decreased 2. Is increased 3. Remains the same Q21. At series resonance, the phase angle between applied voltage and circuit is.. 1. 90 o 2. 180 o 3. 0 o Q22. At parallel resonance, the ratio L/C is.
1. Very large 2. Zero 3. Small Q23. If the resistance of a tuned circuit is increased, the Q of the circuit. 1. Is increased 2. Is decreased 3. Remains the same Q24. The Q of a tuned circuit refers to the property of.. 1. Sensitivity 2. Fidelity 3. Selectivity Q25. At parallel resonance, the phase angle between the applied voltage and circuit current is. 1. 90 o 2. 180 o 3. 0 o Q26. In a parallel LC circuit, if the signal frequency is decreased below the resonant frequency, then 1. X L decreases and X C increases 2. X L increases and X C decreases 3. Line current becomes minimum Q27. In series resonance, there is 1. Voltage amplification 2. Current amplification 3. Both voltage and current amplification
Q28. The Q of a tuned amplifier is generally. 1. Less than 5 2. Less than 10 3. More than 10 Q29. The Q of a tuned amplifier is 50. If the resonant frequency for the amplifier is 1000kHZ, then bandwidth is 1. 10kHz 2. 40 khz 3. 30 khz 4. 20 khz Q30. In the above question, what are the values of cut-off frequencies? 1. 140 khz, 60 khz 2. 1020 khz, 980 khz 3. 1030 khz, 970 khz Q31. For frequencies above the resonant frequency, a parallel LC circuit behaves as a. load 1. Capacitive 2. Resistive 3. Inductive Q32. In parallel resonance, there is 1. Both voltage and current amplification 2. Voltage amplifications 3. Current amplification Q33. For frequencies below resonant frequency, a series LC circuit behaves as a load 1. Resistive 2. Capacitive 3. Inductive
Q34. If a high degree of selectivity is desired, then double-tuned circuit should have. coupling 1. Loose 2. Tight 3. Critical Q35. In the double tuned circuit, if the mutual inductance between the two tuned circuits is decreased, the level of resonance curve.. 1. Remains the same 2. Is lowered 3. Is raised Q36. For frequencies above the resonant frequency, a series LC circuit behaves as a.. load 1. Resistive 2. Inductive 3. Capacitive Q37. Double tuned circuits are used in. stages of a radio receiver 1. IF 2. Audio 3. Output Q38. A class C amplifier always drives. load 1. A pure resistive 2. A pure inductive 3. A pure capacitive 4. A resonant tank Q39. Tuned class C amplifiers are used for RF signals of 1. Low power 2. High power 3. Very high power
Q40. For frequencies below the resonant frequency, a parallel LC circuit behaves as a load 1. Inductive 2. Resistive 3. Capacitive