MCQOPTIONS
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MCQOPTIONS
This section includes 869 Mcqs, each offering curated multiple-choice questions to sharpen your BITSAT knowledge and support exam preparation. Choose a topic below to get started.
| 501. |
The addition of impurity in extrinsic semiconductor is about 1 part in 10⁸ parts. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 502. |
The cascade amplifier is a multistage configuration of |
| A. | CC-CB |
| B. | CE-CB |
| C. | CB-CC |
| D. | CE-CC |
| Answer» C. CB-CC | |
| 503. |
In an insulated gate FET, the polarity of inversion layer is the same as that of |
| A. | minority carriers in source |
| B. | majority carriers in source |
| C. | charge on gate electrode |
| D. | minority carriers in drain |
| Answer» C. charge on gate electrode | |
| 504. |
In a varactor diode the increase in width of depletion layer results in |
| A. | decrease in capacitance |
| B. | increase in capacitance |
| C. | no change in capacitance |
| D. | either (a) or (b) |
| Answer» B. increase in capacitance | |
| 505. |
Assertion (A): In active region of CE output characteristics of BJT, collector current is nearly constant.Reason (R): Base current in CE connection is very small. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true but R is not a correct explanation of A | |
| 506. |
The number of valence electrons in a silicon atom is |
| A. | 4 |
| B. | 2 |
| C. | 1 |
| D. | 0 |
| Answer» B. 2 | |
| 507. |
Which of the following insulating material is restricted to temperatures below 100°C? |
| A. | Micanite |
| B. | Asbestos |
| C. | Teflon |
| D. | Polythene |
| Answer» E. | |
| 508. |
The residual resistivity of a binary alloy at 0°K is |
| A. | the sum of the residual resistivities of the component metals |
| B. | the difference of the residual resistivities of the component metals |
| C. | the product of the residual resistivities of the component metals |
| D. | depend on the concentration of the minor component in the alloy |
| Answer» E. | |
| 509. |
The material which has zero temperature coefficient of resistance is |
| A. | manganin |
| B. | porcelain |
| C. | carbon |
| D. | aluminium |
| Answer» B. porcelain | |
| 510. |
In intrinsic semiconductor, the fermi level |
| A. | lies at the centre of forbidden energy gap |
| B. | is near the conduction band |
| C. | is near the valence band |
| D. | may be anywhere in the forbidden energy gap |
| Answer» B. is near the conduction band | |
| 511. |
Assertion (A): The frequency of light used for photoelectric emission is high.Reason (R): As per Einstein's equation 0.5 mv² < hf - Uw. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true but R is not a correct explanation of A | |
| 512. |
When a BJT is operated under saturated condition |
| A. | both junctions are forward biased |
| B. | both junctions are reverse biased |
| C. | CB junction is forward biased and EB junction is reverse biased |
| D. | EB junction is forward biased and CB junction is reverse biased |
| Answer» B. both junctions are reverse biased | |
| 513. |
Dielectric strength of which of the following material has the highest dielectric strength? |
| A. | Porcelain |
| B. | Soft rubber |
| C. | Glass |
| D. | Joule effect |
| Answer» E. | |
| 514. |
For a n-channel JFET with r₀ = 10 kW, (VGs= 0 V, VP = - 6 V)the drain resistance rd at VGS= - 3 V is given by |
| A. | 40 kΩ |
| B. | 2.5 kΩ |
| C. | 4.44 kW |
| D. | 120 kW |
| Answer» B. 2.5 kΩ | |
| 515. |
Which of the following is a passive component? |
| A. | Semiconductor devices |
| B. | Vacuum tube devices |
| C. | Capacitors |
| D. | All of the above |
| Answer» D. All of the above | |
| 516. |
Which of the following is not a semiconductor? |
| A. | Silicon |
| B. | Calcium arsenide |
| C. | Germanium |
| D. | Zinc sulphide |
| Answer» C. Germanium | |
| 517. |
When an electron rises through a potential of 100 V it will acquired an energy of |
| A. | 100 eV |
| B. | 100 Joules |
| C. | 100 ergs |
| D. | 100 x 10¯⁶ Newtons |
| Answer» B. 100 Joules | |
| 518. |
To ensure that a zener diode does not get destroyed |
| A. | the applied voltage should not exceed breakdown voltage |
| B. | the current should not exceed rated current |
| C. | the current should be less than magnitude of barrier potential |
| D. | both (a) and (b) |
| Answer» C. the current should be less than magnitude of barrier potential | |
| 519. |
Which one of the following gain equations is correct for a MOSFET common-source amplifier?(gm is mutual conductance, and RD is load resistance at the drain) |
| A. | AV = gm/(1 - RD) |
| B. | AV = gm/RD |
| C. | AV = gm/(1 + RD) |
| D. | AV = RD/gm |
| Answer» C. AV = gm/(1 + RD) | |
| 520. |
Fermi level in intrinsic semiconductor is at the centre of forbidden energy band. |
| A. | True |
| B. | False |
| C. | May be True or False |
| D. | Can't say |
| Answer» B. False | |
| 521. |
The ripple factor of power supply is a measure of |
| A. | its filter efficiency |
| B. | diode rating |
| C. | its voltage regulation |
| D. | purity of power output |
| Answer» E. | |
| 522. |
If a coil has diameter 'd' number of turns 'N' and form factor F then the inductance of the coil is proportional to |
| A. | N²dF |
| B. | Nd²F |
| C. | N²d²/F |
| D. | N²d/F |
| Answer» E. | |
| 523. |
A photo diode is |
| A. | forward biased |
| B. | reverse biased |
| C. | either forward or reverse biased |
| D. | unbiased |
| Answer» C. either forward or reverse biased | |
| 524. |
AE 139 is a |
| A. | tunnel diode |
| B. | germanium power transistor |
| C. | photoconductive cell |
| D. | silicon diode |
| Answer» C. photoconductive cell | |
| 525. |
Compared to bipolar junction transistor, a JFET has |
| A. | lower input impedance |
| B. | high input impedance and high voltage gain |
| C. | higher voltage gain |
| D. | high input impedance and low voltage gain |
| Answer» E. | |
| 526. |
If the conductivity of pure germanium is 1.54 siemens/metre, its resistivity in ohm-metre will be nearly |
| A. | 65 |
| B. | 6.5 |
| C. | 0.65 |
| D. | 0.065 |
| Answer» C. 0.65 | |
| 527. |
The resistivity of ferrites is |
| A. | very much lower than that of the ferromagnetic metals |
| B. | slightly lower than that of the ferromagnetic materials |
| C. | slightly higher than that of the ferromagnetic metals |
| D. | very much higher than that of the ferromagnetic metals |
| Answer» E. | |
| 528. |
Fill in the suitable word in the blanks is the following question. The electron in the outermost orbit is called __________ electron. |
| A. | valence |
| B. | covalent |
| C. | acceptor |
| D. | donor |
| Answer» B. covalent | |
| 529. |
For insulators the energy gap is of the order of |
| A. | 0.1 eV |
| B. | 0.7 eV |
| C. | 1.1 eV to 1.2 eV |
| D. | 5 to 15 eV |
| Answer» E. | |
| 530. |
Which of the following pairs of semiconductors and current carriers is correctly matched? |
| A. | Intrinsic : number of electrons = number of holes |
| B. | P type : number of electrons > number of holes |
| C. | N type : number of electrons < number of holes |
| D. | Bulk : neither electrons nor holes |
| Answer» B. P type : number of electrons > number of holes | |
| 531. |
The forbidden energy gap for silicon is |
| A. | 0.12 eV |
| B. | 1.12 eV |
| C. | 0.72 eV |
| D. | 7.2 eV |
| Answer» C. 0.72 eV | |
| 532. |
In which of the following case the rating of the transformer to deliver 100 watts of d.c. power to a load, will be least? |
| A. | Half wave rectifier |
| B. | Full wave rectifier |
| C. | Bridge type full wave rectifier |
| D. | Three phase full wave rectifier |
| Answer» E. | |
| 533. |
In a bipolar transistor |
| A. | recombination in base regions of both n-p-n and p-n-p transistor is low |
| B. | recombination in base regions of both n-p-n and p-n-p transistors is high |
| C. | recombination in base region of n-p-n transistor is low but that in p-n-p transistor is high |
| D. | recombination in base region of p-n-p transistor is low but that in n-p-n transistor is high |
| Answer» B. recombination in base regions of both n-p-n and p-n-p transistors is high | |
| 534. |
Assertion (A): JFET is a voltage controlled device.Reason (R): The drain current can be controlled by controlling VGS. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are true but R is not a correct explanation of A | |
| 535. |
In the forward blocking region of a silicon, controlled rectifier, the SCR is |
| A. | in the off-state |
| B. | in the ON state |
| C. | reverse biased |
| D. | at the point of breakdown |
| Answer» B. in the ON state | |
| 536. |
If E is energy level of electron and EF is Fermi level, then |
| A. | all quantum states with E less than EF will be occupied at T = 0 |
| B. | all quantum states with E less than EF will be empty at T = 0 |
| C. | some quantum states with E less than EF will be occupied at T = 0 |
| D. | none of the above |
| Answer» B. all quantum states with E less than EF will be empty at T = 0 | |
| 537. |
What is the correct sequence of the following step in the fabrication of a monolithic, Bipolar junction transistor? 1. Emitter diffusion2. Base diffusion3. Buried layer formation4. E pi-layer formation Select the correct answer using the codes given below: |
| A. | 3, 4, 1, 2 |
| B. | 4, 3, 1, 2 |
| C. | 3, 4, 2, 1 |
| D. | 4, 3, 2, 1 |
| Answer» E. | |
| 538. |
For a BJT, under the saturation region. |
| A. | IC = βIB |
| B. | IC > βIB |
| C. | IC is independent of other parameter |
| D. | IC < βIB |
| Answer» E. | |
| 539. |
Assertion (A): Field emission is substantially independent of temperature.Reason (R): When a high electric field is created at metal surface field emission may occur. |
| A. | Both A and R are true and R is correct explanation of A |
| B. | Both A and R are true but R is not a correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» C. A is true but R is false | |
| 540. |
The impurity added to extrinsic semiconductor is of the order of |
| A. | 1 in 100 |
| B. | 1 in 1000 |
| C. | 1 in 100, 0000 |
| D. | 1 in 100, 000, 000 |
| Answer» C. 1 in 100, 0000 | |
| 541. |
Higher value of ripple factor indicates |
| A. | poor rectification |
| B. | ideal rectification |
| C. | r.m.s. value to peak value |
| D. | none of the above |
| Answer» B. ideal rectification | |
| 542. |
Fermi level is the amount of energy in which |
| A. | a hole can have at room temperature |
| B. | an electron can have at room temperature |
| C. | must be given to an electron move to conduction band |
| D. | none of the above |
| Answer» D. none of the above | |
| 543. |
In a p type material the Fermi level is 0.3 eV above valence band. The concentration of acceptor atoms is increased. The new position of Fermi level is likely to be |
| A. | 0.5 eV above valence band |
| B. | 0.28 eV above valence band |
| C. | 0.1 eV above valence band |
| D. | below the valence band |
| Answer» C. 0.1 eV above valence band | |
| 544. |
In a degenerate n type semiconductor material, the Fermi level, |
| A. | is in valence band |
| B. | is in conduction band |
| C. | is at the centre in between valence and conduction bands |
| D. | is very near valence band |
| Answer» C. is at the centre in between valence and conduction bands | |
| 545. |
In which of the following device electrons will be the majority carriers? |
| A. | P-type semiconductor |
| B. | N-type semiconductor |
| C. | N-P-N transistor |
| D. | P-N-P transistor |
| Answer» E. | |
| 546. |
Surface leakage current is a part of |
| A. | reverse current |
| B. | forward current |
| C. | reverse breakdown |
| D. | forward breakdown |
| Answer» B. forward current | |
| 547. |
In an integrated circuit the SiO₂ layers provide |
| A. | electrical connection to external Ckt. |
| B. | physical strength |
| C. | isolation |
| D. | conducting path. |
| Answer» D. conducting path. | |
| 548. |
The forbidden band in semiconductors is of the order of |
| A. | 6 eV |
| B. | 1 eV |
| C. | 10 eV |
| D. | 0.01 eV |
| Answer» C. 10 eV | |
| 549. |
Which quantity controls the effectiveness of LED in emitting light? |
| A. | Applied voltage |
| B. | Current |
| C. | Extent of doping |
| D. | Temperature |
| Answer» E. | |
| 550. |
A Si sample is doped with a fixed number of group N impurities. The electron density n is measured from 4 K to 1200 k for the sample. Which one of the following is correct? |
| A. | n remains constant over the temperature range |
| B. | n increases monotonicaliy with increasing temp |
| C. | n increases first remains constant over a range and again increases with increasing temperature |
| D. | n increases show a peak and then decrease with temperature |
| Answer» C. n increases first remains constant over a range and again increases with increasing temperature | |