A Buying Guide for Transistors. Whether youre building, repairing, or maintaining electronics, youll end up needing transistors. Universally useful and adaptable, the transistor is an essential component of electronic circuitry. 38 Games Like Transistor for Mac. From the creators of Bastion, Transistor is a sci-fi themed action RPG that invites you to wield an extraordinary weapon of unknown origin as you fight through a stunning futuristic city. Transistor seamlessly integrates thoughtful strategic planning into a fast-paced action experience, melding responsive. The first commercial applications for transistors were for hearing aids and “pocket” radios during the 1950s. With their small size and low power consumption, transistors were desirable substitutes for the vacuum tubes (known as “valves” in Great Britain) then used to amplify weak electrical signals and produce audible sounds. Transistors also began to replace vacuum. Where to Get Transistor for Mac and Linux: If you have Transistor on Steam, you'll get access to these two new versions auto-magically (and for free!) as part of our latest and biggest update. Thank you again for all your support! Transistor for Mac is also available on the Mac App Store.
Multiple Choice Questions and Answers on Transistors
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Q1. A transistor has …………………
- one pn junction
- two pn junctions
- three pn junctions
- four pn junctions
Answer : 2
Q2. The number of depletion layers in a transistor is …………
- four
- three
- one
- two
Answer : 4
Q3. The base of a transistor is ………….. doped
- heavily
- moderately
- lightly
- none of the above
Answer : 3
Q4. The element that has the biggest size in a transistor is ………………..
- collector
- base
- emitter
- collector-base-junction
Answer : 1
Q5. In a pnp transistor, the current carriers are ………….
- acceptor ions
- donor ions
- free electrons
- holes
Answer : 4
Q6. The collector of a transistor is …………. doped
- heavily
- moderately
- lightly
- none of the above
Answer : 2
Q7. A transistor is a …………… operated device
- current
- voltage
- both voltage and current
- none of the above
Answer : 1
Q8. In a npn transistor, ……………. are the minority carriers
- free electrons
- holes
- donor ions
- acceptor ions
Answer : 2
Q9. The emitter of a transistor is ………………… doped
- lightly
- heavily
- moderately
- none of the above
Answer : 2
Q10. In a transistor, the base current is about ………….. of emitter current
- 25%
- 20%
- 35 %
- 5%
Answer : 4
Q11. At the base-emitter junctions of a transistor, one finds ……………
- a reverse bias
- a wide depletion layer
- low resistance
- none of the above
Answer : 3
Q12. The input impedance of a transistor is ………….
- high
- low
- very high
- almost zero
Answer : 2
Q13. Most of the majority carriers from the emitter ………………..
- recombine in the base
- recombine in the emitter
- pass through the base region to the collector
- none of the above
Answer :3
Q14. The current IB is …………
- electron current
- hole current
- donor ion current
- acceptor ion current
Answer : 1
Q15. In a transistor ………………..
IC = IE + IB
IB = IC + IE
IE = IC – IB
IE = IC + IB
Answer : 4
Q16. The value of α of a transistor is ……….
- more than 1
- less than 1
- 1
- none of the above
Answer : 2
Q17. IC = αIE + ………….
- IB
- ICEO
- ICBO
- βIB
Answer : 3
Q18. The output impedance of a transistor is ……………..
- high
- zero
- low
- very low
Answer : 1
Q19. In a tansistor, IC = 100 mA and IE = 100.2 mA. The value of β is …………
- 100
- 50
- about 1
- 200
Answer : 4
Q20. In a transistor if β = 100 and collector current is 10 mA, then IE is …………
- 100 mA
- 100.1 mA
- 110 mA
- none of the above
Answer : 2
Q21. The relation between β and α is …………..
- β = 1 / (1 – α )
- β = (1 – α ) / α
- β = α / (1 – α )
- β = α / (1 + α )
Answer : 3
Q22. The value of β for a transistor is generally ………………..
- 1
- less than 1
- between 20 and 500
- above 500
Answer : 3
Q23. The most commonly used transistor arrangement is …………… arrangement
- common emitter
- common base
- common collector
- none of the above
Answer : 1
Q24. The input impedance of a transistor connected in …………….. arrangement is the highest
- common emitter
- common collector
- common base
- none of the above
Answer : 2
Q25. The output impedance of a transistor connected in ……………. arrangement is the highest
- common emitter
- common collector
- common base
- none of the above
Answer : 3
Q26. The phase difference between the input and output voltages in a common base arrangement is …………….
- 180o
- 90o
- 270o
- 0o
Answer : 4
Q27. The power gain in a transistor connected in ……………. arrangement is the highest
- common emitter
- common base
- common collector
- none of the above
Answer : 1
Q28. The phase difference between the input and output voltages of a transistor connected in common emitter arrangement is ………………
- 0o
- 180o
- 90o
- 270o
Answer : 2
Q29. The voltage gain in a transistor connected in ………………. arrangement is the highest
- common base
- common collector
- common emitter
- none of the above
Answer : 3
Q30. As the temperature of a transistor goes up, the base-emitter resistance ……………
- decreases
- increases
- remains the same
- none of the above
Answer : 1
Q31. The voltage gain of a transistor connected in common collector arrangement is ………..
- equal to 1
- more than 10
- more than 100
- less than 1
Answer : 4
Q32. The phase difference between the input and output voltages of a transistor connected in common collector arrangement is ………………
- 180o
- 0o
- 90o
- 270o
Answer : 2
Q33. IC = β IB + ………..
- ICBO
- IC
- ICEO
- αIE
Answer : 3
Q34. IC = [α / (1 – α )] IB + ………….
- ICEO
- ICBO
- IC
- (1 – α ) IB
Answer : 1
Q35. IC = [α / (1 – α )] IB + […….. / (1 – α )]
- ICBO
- ICEO
- IC
- IE
Answer : 1
Q36. BC 147 transistor indicates that it is made of …………..
- germanium
- silicon
- carbon
- none of the above
Answer : 2
Q37. ICEO = (………) ICBO
- β
- 1 + α
- 1 + β
- none of the above
Answer : 3
Q38. A transistor is connected in CB mode. If it is not connected in CE mode with same bias voltages, the values of IE, IB and IC will …………..
- remain the same
- increase
- decrease
- none of the above
Answer : 1
Q39. If the value of α is 0.9, then value of β is ………..
- 9
- 0.9
- 900
- 90
Answer : 4
Q40. In a transistor, signal is transferred from a …………… circuit
- high resistance to low resistance
- low resistance to high resistance
- high resistance to high resistance
- low resistance to low resistance
Answer : 2
Q41. The arrow in the symbol of a transistor indicates the direction of ………….
- electron current in the emitter
- electron current in the collector
- hole current in the emitter
- donor ion current
Answer : 3
Q42. The leakage current in CE arrangement is ……………. that in CB arrangement
- more than
- less than
- the same as
- none of the above
Answer : 1
Q43. A heat sink is generally used with a transistor to …………
- increase the forward current
- decrease the forward current
- compensate for excessive doping
- prevent excessive temperature rise
Answer : 4
Q44. The most commonly used semiconductor in the manufacture of a transistor is ………….
- germanium
- silicon
- carbon
- none of the above
Answer : 2
Q45. The collector-base junction in a transistor has ……………..
- forward bias at all times
- reverse bias at all times
- low resistance
- none of the above
Answer : 2
Q46. When transistors are used in digital circuits they usually operate in the ………….
- active region
- breakdown region
- saturation and cutoff regions
- linear region
Answer : 3
Q47. Three different Q points are shown on a dc load line. The upper Q point represents the ………….
- minimum current gain
- intermediate current gain
- maximum current gain
- cutoff point
Answer : 3
Q48. A transistor has a of 250 and a base current, IB, of 20 A. The collector current, IC, equals to …………….
- 500 μA
- 5 mA
- 50 mA
- 5 A
Answer : 2
Q49. A current ratio of IC/IE is usually less than one and is called …………
- beta
- theta
- alpha
- omega
Answer : 3
Q50. With the positive probe on an NPN base, an ohmmeter reading between the other transistor terminals should be ……
- open
- infinite
- low resistance
- high resistance
Answer : 3
Q51. In a CE configuration, an emitter resistor is used for ……
- stabilization
- ac signal bypass
- collector bias
- higher gain
Answer : 1
Q52. Voltage-divider bias provides ……….
- an unstable Q point
- a stable Q point
- a Q point that easily varies with changes in the transistor’s current gain
- a Q point that is stable and easily varies with changes in the transistor’s current gain
Answer : 2
Q53. To operate properly, a transistor’s base-emitter junction must be forward biased with reverse bias applied to which junction?
- collector-emitter
- base-collector
- base-emitter
- collector-base
Answer : 4
Q54. The ends of a load line drawn on a family of curves determine ……
- saturation and cutoff
- the operating point
- the power curve
- the amplification factor
Answer : 1
Q55. If VCC = +18 V, voltage-divider resistor R1 is 4.7 k, and R2 is 1500, then the base bias voltage is ……….
- 8.7 V
- 4.35 V
- 2.9 V
- 0.7 V
Answer: 2
Q56. The C-B configuration is used to provide which type of gain?
- voltage
- current
- resistance
- power
Answer : 1
Q57. The Q point on a load line may be used to determine …………
- VC
- VCC
- VB
- IC
Answer : 3
Q58. A transistor may be used as a switching device or as a ………….
- fixed resistor
- tuning device
- rectifier
- variable resistor
Answer : 4
Q59. If an input signal ranges from 20–40 A (microamps), with an output signal ranging from .5–1.5 mA (milliamps), what is the ac beta?
- 0.05
- 20
- 50
- 500
Answer : 3
Q60. Beta’s current ratio is ……..
- IC/IB
- IC/IE
- IB/IE
- IE/IB
Answer: 1
Q61. A collector characteristic curve is a graph showing ………..
- emitter current (IE) versus collector-emitter voltage (VCE) with (VBB) base bias voltage held constant
- collector current (IC) versus collector-emitter voltage (VCE) with (VBB) base bias voltage held constant
- collector current (IC) versus collector-emitter voltage (VC) with (VBB) base bias voltage held constant
- collector current (IC) versus collector-emitter voltage (VCC) with (VBB) base bias voltage held constant
Answer: 2
Q62. With low-power transistor packages, the base terminal is usually the ……….
- tab end
- middle
- right end
- stud mount
Answer: 2
Q63. When a silicon diode is forward biased, VBE for a CE configuration is ……..
- voltage-divider bias
- 0.4 V
- 0.7 V
- emitter voltage
Answer: 3
Q64. What is the current gain for a common-base configuration where IE = 4.2 mA and IC = 4.0 mA?
- 16.8
- 1.05
- 0.2
- 0.95
Answer: 4
Q65. With a PNP circuit, the most positive voltage is probably …………
- ground
- VC
- VBE
- VCC
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Answer: 1
Q66. If a 2 mV signal produces a 2 V output, what is the voltage gain?
- 0.001
- 0.004
- 100
- 1000
Answer: 4
![Transistor mac download Transistor mac download](/uploads/1/1/9/8/119844979/560085707.jpg)
Q67. Most of the electrons in the base of an NPN transistor flow …………
- out of the base lead
- into the collector
- into the emitter
- into the base supply
Answer: 2
Q68. In a transistor, collector current is controlled by ………..
- collector voltage
- base current
- collector resistance
- all of the above
Answer: 2
Q69. Total emitter current is …………
- IE – IC
- IC + IE
- IB + IC
- IB – IC
Answer: 3
Q70. Often a common-collector will be the last stage before the load; the main function(s) of this stage is to ………….
- provide voltage gain
- provide phase inversion
- provide a high-frequency path to improve the frequency response
- buffer the voltage amplifiers from the low-resistance load and provide impedance matching for maximum power transfer
Answer: 4
Q71. For a CC configuration to operate properly, the collector-base junction should be reverse biased, while forward bias should be applied to …………… junction.
- collector-emitter
- base-emitter
- collector-base
- cathode-anode
Answer: 1
Q72. The input/output relationship of the common-collector and common-base amplifiers is ………..
- 270 degrees
- 180 degrees
- 90 degrees
- 0 degrees
Answer: 4
Q73. If a transistor operates at the middle of the dc load line, a decrease in the current gain will move the Q point ………….
- off the load line
- nowhere
- up
- down
Answer: 4
Q74. Which is the higher gain provided by a CE configuration?
- voltage
- current
- resistance
- power
Answer: 4
Q75. What is the collector current for a CE configuration with a beta of 100 and a base current of 30 A?
- 30 A
- 0.3 A
- 3 mA
- 3 MA
Answer: 3
Check out the ultimate resource onBasic Electronics Questions and Answers . Wth hundreds of chapter-wise questions & answers on Basic Electronics, this is the most comprehensive question bank on the entire internet.
In addition to reading the questions and answers on my site, I would suggest you to check the following, on amazon, as well:
Transistor
- Development of transistors
- Transistor principles
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Michael RiordanProfessor of Physics, Institute for Particle Physics, University of California at Santa Cruz, and Professor of History and Philosophy of Science, Stanford University, Stanford, Calif. Author of Crystal...
Transistor, semiconductor device for amplifying, controlling, and generating electrical signals. Transistors are the active components of integrated circuits, or “microchips,” which often contain billions of these minuscule devices etched into their shiny surfaces. Deeply embedded in almost everything electronic, transistors have become the nerve cells of the Information Age.
Inventors and Inventions
There are typically three electrical leads in a transistor, called the emitter, the collector, and the base—or, in modern switching applications, the source, the drain, and the gate. An electrical signal applied to the base (or gate) influences the semiconductor material’s ability to conduct electrical current, which flows between the emitter (or source) and collector (or drain) in most applications. A voltage source such as a battery drives the current, while the rate of current flow through the transistor at any given moment is governed by an input signal at the gate—much as a faucet valve is used to regulate the flow of water through a garden hose.
Transistor Mac97a6 M922
The first commercial applications for transistors were for hearing aids and “pocket” radios during the 1950s. With their small size and low power consumption, transistors were desirable substitutes for the vacuum tubes (known as “valves” in Great Britain) then used to amplify weak electrical signals and produce audible sounds. Transistors also began to replace vacuum tubes in the oscillator circuits used to generate radio signals, especially after specialized structures were developed to handle the higher frequencies and power levels involved. Low-frequency, high-power applications, such as power-supply inverters that convert alternating current (AC) into direct current (DC), have also been transistorized. Some power transistors can now handle currents of hundreds of amperes at electric potentials over a thousand volts.
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By far the most common application of transistors today is for computer memory chips—including solid-state multimedia storage devices for electronic games, cameras, and MP3 players—and microprocessors, where millions of components are embedded in a single integrated circuit. Here the voltage applied to the gate electrode, generally a few volts or less, determines whether current can flow from the transistor’s source to its drain. In this case the transistor operates as a switch: if a current flows, the circuit involved is on, and if not, it is off. These two distinct states, the only possibilities in such a circuit, correspond respectively to the binary 1s and 0s employed in digital computers. Similar applications of transistors occur in the complex switching circuits used throughout modern telecommunications systems. The potential switching speeds of these transistors now are hundreds of gigahertz, or more than 100 billion on-and-off cycles per second.
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Development of transistors
The transistor was invented in 1947–48 by three American physicists, John Bardeen, Walter H. Brattain, and William B. Shockley, at the American Telephone and Telegraph Company’sBell Laboratories. The transistor proved to be a viable alternative to the electron tube and, by the late 1950s, supplanted the latter in many applications. Its small size, low heat generation, high reliability, and low power consumption made possible a breakthrough in the miniaturization of complex circuitry. During the 1960s and ’70s, transistors were incorporated into integrated circuits, in which a multitude of components (e.g., diodes, resistors, and capacitors) are formed on a single “chip” of semiconductor material.
Motivation and early radar research
Electron tubes are bulky and fragile, and they consume large amounts of power to heat their cathode filaments and generate streams of electrons; also, they often burn out after several thousand hours of operation. Electromechanical switches, or relays, are slow and can become stuck in the on or off position. For applications requiring thousands of tubes or switches, such as the nationwide telephone systems developing around the world in the 1940s and the first electronic digital computers, this meant constant vigilance was needed to minimize the inevitable breakdowns.
An alternative was found in semiconductors, materials such as silicon or germanium whose electrical conductivity lies midway between that of insulators such as glass and conductors such as aluminum. The conductive properties of semiconductors can be controlled by “doping” them with select impurities, and a few visionaries had seen the potential of such devices for telecommunications and computers. However, it was military funding for radar development in the 1940s that opened the door to their realization. The “superheterodyne” electronic circuits used to detect radar waves required a dioderectifier—a device that allows current to flow in just one direction—that could operate successfully at ultrahigh frequencies over one gigahertz. Electron tubes just did not suffice, and solid-state diodes based on existing copper-oxide semiconductors were also much too slow for this purpose.
Crystal rectifiers based on silicon and germanium came to the rescue. In these devices a tungstenwire was jabbed into the surface of the semiconductor material, which was doped with tiny amounts of impurities, such as boron or phosphorus. The impurity atoms assumed positions in the material’s crystal lattice, displacing silicon (or germanium) atoms and thereby generating tiny populations of charge carriers (such as electrons) capable of conducting usable electrical current. Depending on the nature of the charge carriers and the applied voltage, a current could flow from the wire into the surface or vice-versa, but not in both directions. Thus, these devices served as the much-needed rectifiers operating at the gigahertz frequencies required for detecting rebounding microwave radiation in military radar systems. By the end of World War II, millions of crystal rectifiers were being produced annually by such American manufacturers as Sylvania and Western Electric.
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