MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 312 Mcqs, each offering curated multiple-choice questions to sharpen your Banking And Financial Awareness knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Regarding a semiconductor which one of the following is wrong? |
| A. | There are no free electrons at room temperature |
| B. | There are no free electrons at OK |
| C. | The number of free electrons increases with rise of temperature |
| D. | The charge carriers are electrons and holes |
| Answer» B. There are no free electrons at OK | |
| 2. |
An oscillator is nothing but an amplifer with |
| A. | positive feedback |
| B. | negative feedback |
| C. | large gain |
| D. | no feedback |
| Answer» B. negative feedback | |
| 3. |
When a solid with a band gap has a donor level just below its empty energy band, the solid is |
| A. | an insulator |
| B. | a conductor |
| C. | p-type semiconductor |
| D. | n-type semiconductor |
| Answer» E. | |
| 4. |
When n-p-n transistor is used as an amplifier |
| A. | electrons move from collector to base |
| B. | holes move from emitter to base |
| C. | electrons move from base to collector |
| D. | holes move from base to emitter |
| Answer» E. | |
| 5. |
In a common base amplifier the phase difference between the input signal voltage and the output voltage is |
| A. | 0 |
| B. | \[\pi /4\] |
| C. | \[\pi /2\] |
| D. | \[\pi \] |
| Answer» B. \[\pi /4\] | |
| 6. |
When a p-n junction diode is reverse biased the flow of current across the junction is mainly due to |
| A. | diffusion of charges |
| B. | drift of charges |
| C. | depends on the nature of material |
| D. | both drift and diffusion of charges |
| Answer» C. depends on the nature of material | |
| 7. |
When an n-p-n transistor is used as an amplifier then |
| A. | electrons flow from emitter to collector |
| B. | holes flow from emitter to collector |
| C. | electrons flow from collector to emitter |
| D. | electrons flow from battery to emitter |
| Answer» B. holes flow from emitter to collector | |
| 8. |
If you go on increasing the stretching force on a wire in a guitar, its frequency. |
| A. | increases |
| B. | decreases |
| C. | remains unchanged |
| D. | None of these |
| Answer» B. decreases | |
| 9. |
A vibrating body |
| A. | will always produce sound |
| B. | may or may not produce sound if the amplitude of vibration is low |
| C. | will produce sound which depends upon frequency |
| D. | None of these |
| Answer» D. None of these | |
| 10. |
The velocity of sound is largest in |
| A. | water |
| B. | air |
| C. | metal |
| D. | vacuum |
| Answer» D. vacuum | |
| 11. |
An underwater explosion is caused near the sea-shore. There are two observers, X under water and Yon land, each at a distance of 1 km from the point of explosion then |
| A. | X Twill hear the sound earlier |
| B. | y will hear the sound earlier |
| C. | Both will hear the sound at the same time |
| D. | Y will not hear the sound at all |
| Answer» B. y will hear the sound earlier | |
| 12. |
In an n-type silicon, which of the following statement is true? |
| A. | Electrons are majority carriers and trivalent atoms are the dopants. |
| B. | Electrons are minority carriers and pentavalent atoms are the dopants. |
| C. | Holes are minority carriers and pentavalent atoms are the dopants. |
| D. | Holes are majority carriers and trivalent atoms are the dopants. |
| Answer» D. Holes are majority carriers and trivalent atoms are the dopants. | |
| 13. |
Which of the statements is true for p-type semiconductors?? |
| A. | Electrons are majority carriers and trivalent atoms are the dopants. |
| B. | Electrons are minority carriers and pentavalent atoms are the dopants. |
| C. | Holes are minority carriers and pentavalent atoms are the dopants. |
| D. | Holes are majority carriers and trivalent atoms are the dopants. |
| Answer» E. | |
| 14. |
If the conductivity of a semiconductor is only due to break up of the covalent bonds due to thermal excitation, then the semiconductor is called |
| A. | intrinsic |
| B. | extrinsic |
| C. | donor |
| D. | acceptor |
| Answer» B. extrinsic | |
| 15. |
The mobility of conduction electrons is greater than that of holes, since electrons |
| A. | are lighter |
| B. | are negatively charged |
| C. | require smaller energy for moving through crystal lattice |
| D. | undergo smaller number of collisions |
| Answer» D. undergo smaller number of collisions | |
| 16. |
Range of audio-frequencies is |
| A. | 1-15 Hz |
| B. | 20-20,000 Hz |
| C. | \[{{10}^{3}}-{{10}^{5}}Hz\] |
| D. | \[{{10}^{6}}-{{10}^{8}}Hz\] |
| Answer» C. \[{{10}^{3}}-{{10}^{5}}Hz\] | |
| 17. |
The marching soldiers break steps while crossing a bridge because of |
| A. | damped oscillations |
| B. | resonance |
| C. | echo |
| D. | reverberation |
| Answer» C. echo | |
| 18. |
To obtain a p-type germanium semiconductor, it must be doped with |
| A. | arsenic |
| B. | antimony |
| C. | indium |
| D. | phosphorus |
| Answer» D. phosphorus | |
| 19. |
The frequency of a wave travelling at a speed of 500 \[m{{s}^{-1}}\] is 25Hz. Its time period is |
| A. | 20s |
| B. | 0.05s |
| C. | 25s |
| D. | 0.04s |
| Answer» E. | |
| 20. |
The velocity of sound in any gas depends upon |
| A. | wavelength of sound only |
| B. | density and elasticity of gas |
| C. | intensity of sound waves only |
| D. | amplitude and frequency of sound |
| Answer» C. intensity of sound waves only | |
| 21. |
A shrill sound has a ____ pitch and a dull sound has a___ pitch. |
| A. | high, low |
| B. | low, high |
| C. | low, low |
| D. | high, high |
| Answer» B. low, high | |
| 22. |
is the characteristic of a musical sound by which a loud sound can be distinguished from a faint sound even though both have the same pitch. |
| A. | Loudness |
| B. | Pitch |
| C. | Quality |
| D. | None of these |
| Answer» B. Pitch | |
| 23. |
The energy band gap is minimum in |
| A. | metals |
| B. | superconductors |
| C. | insulators |
| D. | semiconductors. |
| Answer» B. superconductors | |
| 24. |
Which one of the following is not a correct statement about semiconductors? |
| A. | The electrons and holes have different mobilities in a semiconductor |
| B. | In an n-type semiconductor, the Fermi level lies closer to the conduction band edge |
| C. | Silicon is a direct band gap semiconductor |
| D. | Silicon is has diamond structure |
| Answer» D. Silicon is has diamond structure | |
| 25. |
The part of the transistor which is heavily doped to produce large number of majority carriers is |
| A. | emitter |
| B. | base |
| C. | collector |
| D. | any of the above depending upon the nature of transistor |
| Answer» B. base | |
| 26. |
To use a transistor as an amplifier |
| A. | The emitter base junction is forward biased and the base collector junction is reverse biased |
| B. | no bias voltage is required |
| C. | both junctions are forward biased |
| D. | both junctions are reverse biased |
| Answer» B. no bias voltage is required | |
| 27. |
In an intrinsic semiconductor |
| A. | only electrons are responsible for flow of current |
| B. | both holes and electrons carry current |
| C. | both holes and electrons carry current with electrons being majority carriers |
| D. | only holes are responsible for flow of current |
| Answer» C. both holes and electrons carry current with electrons being majority carriers | |
| 28. |
A piece of copper and another of germanium are cooled from room temperature to 80 K. The resistance of |
| A. | each of them increases |
| B. | each of them decreases |
| C. | copper increases and germanium decreases |
| D. | copper decreases and germanium increases |
| Answer» E. | |
| 29. |
When a forward bias is applied to a p-n junction, it |
| A. | raises the potential barrier. |
| B. | reduces the majority carrier current to zero. |
| C. | lowers the potential barrier. |
| D. | None of these |
| Answer» D. None of these | |
| 30. |
Zener diode is used as |
| A. | half wave rectifier |
| B. | full wave rectifier |
| C. | A.C. voltage stabilizer |
| D. | D.C. voltage stabilizer |
| Answer» D. D.C. voltage stabilizer | |
| 31. |
The potential barrier, in the depletion layer, is due to |
| A. | ions |
| B. | holes |
| C. | electrons |
| D. | both [b] and [c] |
| Answer» B. holes | |
| 32. |
p-n junction diode works as a insulator, if connected |
| A. | to A.C. |
| B. | in forward bias |
| C. | in reverse bias |
| D. | None of these |
| Answer» D. None of these | |
| 33. |
For a transistor amplifier, the voltage gain |
| A. | remains constant for all frequencies. |
| B. | is high at high and low frequencies and constant in the middle frequency range. |
| C. | is low at high and low frequencies and constant at mid frequencies. |
| D. | none of the above |
| Answer» D. none of the above | |
| 34. |
One way in which the operation of an n-p-n transistor differs from that of zip-n-p |
| A. | the emitter junction is reverse biased in n-p-n. |
| B. | the emitter junction injects minority carriers into base region of the p-n-p |
| C. | the emitter injects holes into the base of the p-n-p and electrons into the base region n-p-n |
| D. | the emitter injects holes into the base of n-p-n |
| Answer» D. the emitter injects holes into the base of n-p-n | |
| 35. |
An alternating current can be converted into direct current by a |
| A. | rectifier |
| B. | transformer |
| C. | dynamo |
| D. | motor |
| Answer» B. transformer | |
| 36. |
n-p-n transistors are preferred to p-n-p transistors because: |
| A. | they have low cost |
| B. | they have low dissipation energy |
| C. | they are capable of handling large power |
| D. | electrons have high mobility than holes and hence high mobility of energy |
| Answer» E. | |
| 37. |
Voice of your friend can be recognized by its |
| A. | pitch |
| B. | quality |
| C. | intensity |
| D. | velocity |
| Answer» C. intensity | |
| 38. |
The ratio of the speed of a body to the speed of sound is called |
| A. | Sonic index |
| B. | Doppler ratio |
| C. | Mach number |
| D. | Refractive index |
| Answer» D. Refractive index | |
| 39. |
Ultrasonic waves have frequency |
| A. | below 20 Hz |
| B. | between 20 and 20,000 Hz |
| C. | only above 20,000 Hz |
| D. | only above 20,000 MHz |
| Answer» D. only above 20,000 MHz | |
| 40. |
If a tunnel is dug along the diameter of earth and a piece of stone is dropped into it, then the stone will |
| A. | come out of the another end of the earth and will escape out in space |
| B. | come to rest at the centre of the earth |
| C. | start oscillating about the centre of the earth |
| D. | stop at another end of the earth |
| Answer» D. stop at another end of the earth | |
| 41. |
Which of the following statements is incorrect regarding the time period of a simple pendulum oscillating with small amplitude? The time period of the pendulum |
| A. | is inversely proportional to \[\sqrt{g}\] |
| B. | is directly proportional to \[\sqrt{l}\] |
| C. | does not depend upon the amplitude |
| D. | depends upon its mass, material and shape |
| Answer» E. | |
| 42. |
The energy band gap is maximum in |
| A. | metals |
| B. | super conductors |
| C. | insulators |
| D. | semiconductors |
| Answer» D. semiconductors | |
| 43. |
The part of a transistor which is most heavily doped to produce large number of majority carriers is |
| A. | emmiter |
| B. | base |
| C. | collector |
| D. | can be any of the above three |
| Answer» B. base | |
| 44. |
The wavelength of infrasonics in air is of the order of |
| A. | \[10{}^\circ m\] |
| B. | \[{{10}^{1}}m\] |
| C. | \[{{10}^{-1}}m\] |
| D. | \[{{10}^{-2}}m\] |
| Answer» C. \[{{10}^{-1}}m\] | |
| 45. |
If you are at open-air concert and someone's head gets between you and the orchestra, you can still hear the orchestra because |
| A. | sound waves pass easily through a head |
| B. | a head is not very large compared with the wavelength of the sound |
| C. | the sound is reflected from the head |
| D. | the wavelength of the sound is much smaller than the head |
| Answer» C. the sound is reflected from the head | |
| 46. |
Which impurity is doped in Si to form n-type semiconductors? |
| A. | Al |
| B. | B |
| C. | As |
| D. | None of these |
| Answer» D. None of these | |
| 47. |
Inverter converts |
| A. | alternating current into direct current |
| B. | direct current into alternating current |
| C. | current at low voltage to current at high voltage |
| D. | None of these |
| Answer» C. current at low voltage to current at high voltage | |
| 48. |
Transistors are essentially |
| A. | power driven devices |
| B. | current driven devices |
| C. | voltage driven devices |
| D. | resistance driven devices |
| Answer» C. voltage driven devices | |
| 49. |
In a transistor |
| A. | emitter is more highly doped than collector |
| B. | collector is more highly doped than emitter |
| C. | both are equally doped |
| D. | None of the above |
| Answer» B. collector is more highly doped than emitter | |
| 50. |
In the symbol of a transistor , the arrow head points in the direction of flow of |
| A. | holes |
| B. | electrons |
| C. | majority carriers |
| D. | minority carriers |
| Answer» B. electrons | |