MCQOPTIONS
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MCQOPTIONS
This section includes 38 Mcqs, each offering curated multiple-choice questions to sharpen your Analog Electronics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A CB amplifier has re = 6 , RL = 600 and a = 0.98. The voltage gain is |
| A. | 100 |
| B. | 600 x 0.98 |
| C. | 98 |
| D. | 6 |
| Answer» D. 6 | |
| 2. |
Consider the following statements : A clamper circuit 1.adds or subtracts a dc voltage to a waveform 2.does not change the waveform 3.amplifiers the waveform Which are correct? |
| A. | 1, 2 |
| B. | 1, 3 |
| C. | 1, 2, 3 |
| D. | 2, 3 |
| Answer» B. 1, 3 | |
| 3. |
A forward voltage of 9 V is applied to a diode in series with a 1 k load resistor. The voltage across load resistor is zero. It indicates that |
| A. | diode is short circuited |
| B. | diode is open circuited |
| C. | resistor is open circuited |
| D. | diode is either short circuited or open circuited |
| Answer» C. resistor is open circuited | |
| 4. |
Assertion (A): CE amplifier is the most widely used BJT amplifier Reason (R): CE amplifier has zero phase difference between input and output |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» D. A is wrong R is correct | |
| 5. |
Assertion (A): For large signal variations an amplifier circuit has to be analysed graphically Reason (R): The output characteristics of a transistor is nonlinear. |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» B. Both A and R are correct but R is not correct explanation for A | |
| 6. |
In a BJT circuit a pnp transistor is replaced by npn transistor. To analyse the new circuit |
| A. | all calculations done earlier have to be repeated |
| B. | replace all calculated voltages by reverse values |
| C. | replace all calculated currents by reverse values |
| D. | replace all calculated voltages and currents by reverse values |
| Answer» E. | |
| 7. |
The load impedance ZL of a CE amplifier has R and L in series. The phase difference between output and input will be |
| A. | 180 |
| B. | more than 90 but less than 180 |
| C. | more than 180 but less than 270 |
| D. | more than 180 but less than 270 |
| Answer» E. | |
| 8. |
For a base current of 10 A, what is the value of collector current in common emitter if dc = 100 |
| A. | 10 A |
| B. | 100 A |
| C. | 1 mA |
| D. | 10 mA |
| Answer» D. 10 mA | |
| 9. |
The quiescent collector current IC, and collector to emitter voltage VCE in a CE connection are the values when |
| A. | ac signal is zero |
| B. | ac signal is low |
| C. | ac signal is negative |
| D. | either (a) or (b) |
| Answer» B. ac signal is low | |
| 10. |
A half wave diode rectifier has a capacitance input filter. If input voltage is Vm sin t, PIV is |
| A. | Vm |
| B. | 2 V |
| C. | C. |
| D. | m |
| E. | 4 V |
| Answer» C. C. | |
| 11. |
A transistor with a = 0.9 and ICBO = 10 A is biased so that IBQ = 90 A. Then IEQ will be |
| A. | 5.15 mA |
| B. | 5.2 mA |
| C. | 5 mA |
| D. | 990 mA |
| Answer» E. | |
| 12. |
A bridge rectifier circuit has input of 50 Hz frequency. The load resistance is RL and filter capacitance is C. For good output wave shape, the time constant RLC should be at least equal to |
| A. | 10 ms |
| B. | 20 ms |
| C. | 50 ms |
| D. | 100 ms |
| Answer» E. | |
| 13. |
Assertion (A): Negative feedback reduces the bandwidth of an amplifier Reason (R): Negative feedback stabilizes the gain of an amplifier |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» E. | |
| 14. |
Assertion (A): In a full wave rectifier output the lowest ac component is at twice the input frequency Reason (R): In a full wave rectifier, the output waveform consists of half sinusoids |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» C. A is correct R is wrong | |
| 15. |
The value of parameter re used in re transistor model |
| A. | increases with increase in temperature |
| B. | decreases with increase in temperature |
| C. | is not affected by increase in temperature |
| D. | either (b) or (c) |
| Answer» B. decreases with increase in temperature | |
| 16. |
In following figure find VGG by assuming gate current is negligible for the p-channel JFET. (if IDQ = - 6 mA, RS = 0, VDD = -18 V, RD = 2 k , IDSS = - 10 mA, IPO = - 3 V) |
| A. | 0.67 V |
| B. | 6.7 V |
| C. | 7 V |
| D. | 0.3 V |
| Answer» B. 6.7 V | |
| 17. |
The gain of an FET amplifier can be changed by changing |
| A. | r |
| B. | B. |
| C. | m |
| D. | R |
| E. | D. |
| Answer» C. m | |
| 18. |
A typical value of gm for a FET is about 25 s. |
| A. | True |
| B. | False |
| Answer» C. | |
| 19. |
A transistor has two p-n junctions. The batteries should be connected such that |
| A. | both junctions are forward biased |
| B. | both junctions are reverse biased |
| C. | one junction is forward biased and the other is reverse biased |
| D. | either (a) or (b) |
| Answer» D. either (a) or (b) | |
| 20. |
In following figure find VDSQ by assuming gate current is negligible for the p-channel JFET. (if IDQ = - 6 mA, RS = 0, VDD = -18 V, RD = 2 k , IDSS = - 10 mA, IPO = - 3 V) |
| A. | 4 V |
| B. | - 6 V |
| C. | - 10 V |
| D. | 6 V |
| Answer» C. - 10 V | |
| 21. |
The current flowing in a certain P-N junction at room temperature is 2 x 10-7 Amp. When a large reverse biased voltage is applied. Calculate the current flowing when 0.1 volts is applied. |
| A. | 9 A |
| B. | 10 A |
| C. | 2 A |
| D. | 4 A |
| Answer» B. 10 A | |
| 22. |
Two CE stages, 1 and 2 are coupled through a capacitor. VCC is the same for both. Base resistances RB1 and RB2 are such that RB1 > RB2. Then |
| A. | base currents for both stages are equal |
| B. | base current of stage 1 is more than that of stage 2 |
| C. | base current of stage 2 is more than that of stage 1 |
| D. | either (b) or (c) |
| Answer» D. either (b) or (c) | |
| 23. |
A potential of 7 V is applied to a silicon diode. A resistance of 1 k is also connected in series. If the diode is forward biased, the current in the circuit is |
| A. | 7 mA |
| B. | 6.3 mA |
| C. | 0.7 mA |
| Answer» C. 0.7 mA | |
| 24. |
Calculate the conductivity of pure silicon at room temperature when the concentration of carriers is 1.6 x 1010 per cm3. Take e = 1500 cm2/V-sec, h = 500 cm2/V-sec at room temperature, |
| A. | 5.12 x 10-16 |
| B. | 5 x 10+16 |
| C. | 1016 |
| D. | 5 x 1020 |
| Answer» B. 5 x 10+16 | |
| 25. |
The parameter h11 for CB circuit is higher than that for CE circuit. |
| A. | True |
| B. | False |
| Answer» C. | |
| 26. |
In a voltage regulated power supply the zener operates in the breakdown region when (Vin is input voltage and Vz is zener breakdown voltage) |
| A. | Vin < V |
| B. | B. |
| C. | C. |
| D. | z |
| E. | both (a) or (b) |
| Answer» C. C. | |
| 27. |
For a BJT if = 50, ICEO = 3 A and IC = 1.2 mA then IB |
| A. | 24 A |
| B. | 23 A |
| C. | 20 A |
| D. | 10 A |
| Answer» B. 23 A | |
| 28. |
The units of transistor h parameters h11 and h22 are the same. |
| A. | True |
| B. | False |
| Answer» C. | |
| 29. |
In a transistor CE mode, VCC = +30 V. If the transistor is in cut off region, VCE = |
| A. | +30 V |
| B. | +20 V |
| C. | 10 V |
| D. | zero |
| Answer» B. +20 V | |
| 30. |
A P-channel MOSFET operating in the enhancement mode is characterized by Vt = - 4 V and IDQ = - 10 mA, when VGSQ = - 5.5 V, what will be VGSQ if IDQ = -15 mA and ID, on = - 16 mA |
| A. | - 2 V |
| B. | 3 V |
| C. | 0.13 V |
| D. | 1.3 V |
| Answer» D. 1.3 V | |
| 31. |
Assertion (A): In CE amplifier the emitter is at ground potential for ac signals Reason (R): A CE amplifier has near unity voltage gain |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» D. A is wrong R is correct | |
| 32. |
A full wave rectifier supplies a load of 1 k . The a.c. Voltage applied to the diodes is 220 - 0 - 220 Volts rms. If diode resistance is neglected, then Average d.c. Voltage |
| A. | 220 V |
| B. | 200 V |
| C. | 198 V |
| D. | 0 volts |
| Answer» D. 0 volts | |
| 33. |
An amplifier has input impedance of 4 k and output impedance of 80 k . It is used in negative feedback circuit with 10?edback. If open loop gain is 90, the closed loop input and output impedances are |
| A. | 40 k and 8 k respectively |
| B. | 4 k and 80 k respectively |
| C. | 0.4 k and 800 k respectively |
| D. | 8 k and 160 k respectively |
| Answer» B. 4 k and 80 k respectively | |
| 34. |
N-channel FETs are superior to p-channel FETs because |
| A. | mobility of electrons is smaller than that of holes |
| B. | mobility of electrons is greater than that of holes |
| C. | they consume less power |
| D. | they have high switching time |
| Answer» C. they consume less power | |
| 35. |
The minimum gate source voltage that creates the n-type inversion layer is called |
| A. | cut off voltage |
| B. | on voltage |
| C. | threshold voltage |
| D. | zener voltage |
| Answer» D. zener voltage | |
| 36. |
Assertion (A): Class A and Class B amplifier predominate in audio applications. Reason (R): Class C amplifier is used at radio frequencies. |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» C. A is correct R is wrong | |
| 37. |
Assertion (A): The gain of an FET amplifier can be changed by changing gm Reason (R): Most receivers use automatic gain control to counteract changes in volume caused by fading |
| A. | Both A and R are correct and R is correct explanation for A |
| B. | Both A and R are correct but R is not correct explanation for A |
| C. | A is correct R is wrong |
| D. | A is wrong R is correct |
| Answer» C. A is correct R is wrong | |
| 38. |
The signal input to a given amplifier is made up of 100 m signal power and 1 m noise power. The amplifier contributes an additional 100 m of noise and has a power gain of 20 dB. The noise factor is |
| A. | 1 |
| B. | 1.5 |
| C. | 2.0 |
| D. | 15 |
| Answer» D. 15 | |