Computer Science FAQ

The Thevenin resistance is equal in value to the
Most AC power is obtained from:
The value of a capacitor can be made larger by:
The primary impedance of a transformer is 60 ohm and the secondary impedance is 120 ohm. What is the impedance ratio?
Suppose a voltage source has an ideal voltage of 12V and an internal resistance of 0.5W. For what values of load resistance will the voltage source appear stiff?
Electron current is flowing through a conductor in a direction you might describe as straight into this page. What is the direction of the resulting magnetic field?
Which one of the following principles best describes the basic operation of an electromagnet?
The transistor has a collector current of 2 mA. If the current gain is 135, what is the base current?
Current and voltage are said to be in phase when:
Silicon atoms combine into an orderly pattern called a
The rotating coil of wire in an electric motor is called the:

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The north pole of a magnet is the one:
A resistor has a rated value of 100 ohm and a tolerance of 10%. What is its minimum and maximum allowable resistance value?
When a parallel RLC circuit is operating at its resonant frequency:
For normal operation of the transistor, the collector diode has to be
In a step-down transformer, which is larger?
What is the barrier potential of a silicon diode at room temperature?
The Norton current is sometimes called the
At room temperature a conductor has low many holes?
A current source has an internal resistance of 100 kW. What is the largest load resistance if the current source must appear stiff?
When the Q point moves along the load line, the voltage increases when the current
What is the smallest number of polarities required for current flow?
A diode is in series with 220W. If the voltage across the resister is 4V, what is the current through the diode?
Two diodes are in series. The first diode has a voltage of 0.75 V and the second has a voltage of 0.8 V. If the current through the first diode is 500 mA, what is the current through the second diode
The graph of current gain versus collector current indicates that the current gain
Which one of the following statements is true for the currents in a parallel RL circuit?
What is the impedance of a circuit composed of a 100 ohm resistor connected in parallel with an inductor that has a reactance of 200 W?
The nucleus of the copper atom contains how many protons?
Which one of the following statements is true for voltage in a series circuit?
A basic capacitor is composed of:
Which one of the following devices is most often used for measuring electrical potential difference?
Which one of the following statements most accurately applies to the frequency of a waveform?
The merging of a free electron and a hole is called
One henry of inductance is defined as:
The basic unit of measurement for current is the:
Which one of. the following phrases most accurately describes the nature of a pulsating dc voltage?
An audio transformer has a turn ratio of 9, What is its impedance ratio?
Which one of the following statements is true?
How many protons does the nucleus of a silicon atom contain?
A circuit has two different voltage sources that are connected in a series-opposing form. If the sources are rated at 6 V and 9 V, what is the total source voltage?
The emitter diode is usually
Which one of the following statements is true for the impedance of a series RC circuit?
If a transistor operates at the middle of the load line, an increase in the current gain will move the Q point
What is the turns ratio of a power transformer that shows 50 V at its secondary winding when you apply 150 V to its primary winding?
What is the inductive reactance of a 0.1-H coil that is operating at 1000 Hz?
Which one of the following is a statement of KirchhofFs voltage law?
What is the impedance of a circuit composed of a 100 ohm resistor connected in parallel with a capacitor that has a reactance of 100 ohm?
Current can flow through a normally open push button switch as long as:
Doubling the operating frequency of a purely capacitive circuit:
How much current flows through a 0.02 micro F capacitor that is operating from a 12-V ac, 100-Hz source?
An unloaded zener regulator has a source voltage of 20 V, a series resistance of 330 W, and a zener voltage of 12 V, What is the Zener current?
The total capacitance of a series capacitor circuit is:
Assuming 100% efficiency, what is the power being applied to the primary winding of the transformer described in the above question?
To get the Thevenin voltage, you have to
Which one of the following properties of a magnetic circuit can be directly compared to resistance in an electrical circuit?
When operating above its resonant frequency, a parallel RLC circuit has the characteristics of a:
Doubling the operating frequency of an inductive circuit:
A circuit has a Norton current of 10 mA and a Norton resistance of 10 kW. What is the Thevenin circuit?
A power transformer steps 100 V down to 10 V. If the current in its primary winding is 2 A, what is the current in the secondary winding?
If a load resistance is 1 kW, a stiff voltage source has a resistance of
A typical light switch in your home is a:
Suppose the voltage from a power outlet is 120 Vrms. What is the peak voltage?
A device that converts thermal energy to electrical energy is called a:
How much power is being dissipated by a 1000 W resistance that has 25 V applied to it?
A device that converts chemical energy to electrical energy is called a:
Suppose the peak value of a sinusoidal voltage is 50 V. What is the rms value?
What is the difference between a conductor and an insulator?
A circuit has two different voltage sources that are connected in a series-aiding form. If the sources are rated at 6 V and 9 V, what is the total source voltage?
At room temperature an intrinsic semiconductor has
If the base supply voltage increases, the Q point moves
Positive ions are atoms that have
Which one of the following is a statement of Kirchhoffs current law?
A zener diode has a voltage of 10 V and a current of 20 mA. What is the power dissipation?
Which one of the following phrasers best describes flux density?
Which is the most widely used semiconductor?
The transistor has a current gain of 175. If the base current is 0.1 mA, what is the collector current?
An intrinsic semiconductor has some holes in it at room temperature. What causes these holes?
Which one of the following statements is true for the voltages in a series RL circuit?
The core of an electromagnet is said to be in saturation when:
As the temperature increases, the current gain
Assuming 100% efficiency, what is the power being consumed at the secondary winding of the transformer described in question 91?
Doubling the diameter of the coil in an inductor:
Which one of the following statements regarding ac circuits is correct?
Which one of the following statements most accurately describes the nature of inductive reactance?
What are the main parts of an atom?
Current is
A real voltage source has
What is a free electron?
To get the Norton current, you have to
The barrier potential accross each depletion layer is
Which one of the following properties of a magnetic circuit can be directly compared to voltage in an electrical circuit?
What kind of battery is most likely included in a cordless electric knife?
The basic unit of measurement for resistance is the:
What is the phase shift between total current and voltage, if 100 ohm resistor connected in parallel with an inductor that has a reactance of 200W?
When operating below its resonant frequency, a series RLC circuit has the characteristics of a:
The valence electron of a copper atom experiences what kind of attraction toward the nucleus?
Suppose a step-down transformer has a turns ration of 5:1. If the secondary current is 1A rms, what is the primary-current?
Absolute Zero temperature equals
At cut off, the Q point is at
The south pole of a magnet is the one:
The peak value of a sine waveform is:
Which one of the following statements is true for voltage in a parallel circuit?
The dielectric constant of a material is a measure of:
What is the inductive reactance of a 2-H coil operating at 60 Hz?
When operating above its resonant frequency, a series RLC circuit has the characteristics of a:
What is the primary difference between primary and secondary cell batteries?
Which one of the following statements applies to common auto batteries?
Which one of the following equations most directly determines the power dissipation of a resistance when you know the power dissipation of a resistance when you know the voltage drop and current?
If N1/N2 = 2, and the primary voltage is 120 V, what is the secondary voltage?
A device that converts light energy to electrical energy is called a:
How much current flows through a 60-W light bulb that is operating at 120 V?
What is the power dissipation of a resistance that has 24 V dropped across it and 0.25 A flowing through it?
Which one of the following kinds of materials has the highest permeability?
Inductive reactance is measured in units of:
What is the difference between the kinds of charges for an electron and a proton?
An ideal voltage source has
A transistor has how many doped regions?
The voltage across a 1N4001 is 0.93V when the current is 1A. What is the power dissipation of the diode for these values?
A loadstone is:
Which one of the following phrases most accurately describes a purely capacitive circuit?
The saturation point is approximately the same as
Which one of the following statements is true for the currents in a series RC circuit?
Determine the resistance value and tolerance of a resistor that has the following color bands; first band is red, second band is red, third band is orange, and the fourth band is gold
Which one of the following is most likely used for measuring the rate of electron flow?
Suppose a voltage source has an ideal voltage of 15V and a source resistance of 0.2W. For what values of load resistance will the voltage source appear stiff?
1 Microfarad is the same as:
Which one of the following statements is true for resistance in a parallel circuit?
The direction of conventional current flow is:
Doubling the operating frequency of a purely inductive circuit:
The secondary voltage for a certain power transformer is twice the voltage applied to the primary. The current flowing in the secondary winding will be:
Which one of the following statements best applies to a series RLC circuit?
When applying a square waveform to a capacitor, the circuit tends to:
Which one of the following properties of a magnetic circuit can be directly compared to current in an electrical circuit?
Who invented the first junction transistor?
When a series RLC circuit is operating at its resonant frequency:
Which one of the following equations most directly leads to the resistance of an ordinary household light bulb, assuming that you know the power and voltage rating?
The total capacitive reactance of a parallel capacitor circuit is:
Thevenin theorem replaces a complicated circuit facing a load by an
What kind of device is a diode?
Which one of the following statements applies to common, non-rechargeable flashlight batteries?
The total inductive reactance of a parallel inductor circuit is:
A step-down transformer has turns ration of 5:1. If the primary voltage is 120 Vrms, what is the secondary voltage?
Norton's theorem replaces a complicated circuit facing a load by an
Doubling the operating frequency of a capacitive circuit:
The net charge of a neutral copper atom is
Which one of the following statements is true for the voltage in a parallel RL circuit?
A low-pass filter:
What is one important thing transistors do?
At room temperature an intrinsic silicon crystal acts approximately like
What is the algebraic sum of this series of values:+2, -3, -6,+4?
When operating below its resonant frequency, a parallel RLC circuit has the characteristics of a:
What causes the depletion layer?
Which one of the following statements most accurately reflects the nature of ac power?
A step-up transformer has a turns ratio of 1:4. If the line voltage is 115 V rms, what is the peak secondary voltage?
Which one of the following principles best describes the basic operation of a generator?
The current gain of a transistor is defined as the ratio of the collector current to the
What is the total resistance of a parallel circuit that contains two resistors having values of 220 ohm and 470 ohm?
The equivalent of 1 kV is:
The period of a waveform is:
What is the total resistance of a series circuit that contains four resistors having values of 220W, 470W, 1W, and 1.2W?
Holes act like:
How may valence electrons does a silicon atom have?
Reducing the amount of current through an inductor:
One example of the use of an S-R flip-flop is as a(n):
If both inputs of an S-R NAND latch are LOW, what will happen to the output?
The equation for the output frequency of a 555 timer operating in the astable mode is: . What value of C1 will be required if R1 = 1 k, R2 = 1 k, and f = 1 kHz?
An astable multivibrator is a circuit that:
What is another name for a one-shot?
The truth table for an S-R flip-flop has how many VALID entries?
What is the significance of the J and K terminals on the J-K flip-flop?
Which of the following describes the operation of a positive edge-triggered D-type flip-flop?
What is one disadvantage of an S-R flip-flop?
Which of the following is correct for a gated D-type flip-flop?
When both inputs of a J-K flip-flop cycle, the output will:
Latches constructed with NOR and NAND gates tend to remain in the latched condition due to which configuration feature?
The 555 timer can be used in which of the following configurations?
A basic S-R flip-flop can be constructed by cross-coupling which basic logic gates?
Exclusive-OR (XOR) logic gates can be constructed from what other logic gates?
How many truth table entries are necessary for a four-input circuit?
A NAND gate has:
The basic logic gate whose output is the complement of the input is the:
What input values will cause an AND logic gate to produce a HIGH output?
The output will be a LOW for any case when one or more inputs are zero in a(n):
If a signal passing through a gate is inhibited by sending a low into one of the inputs, and the output is HIGH, the gate is a(n):
A single transistor can be used to build which of the following digital logic gates?
The logic gate that will have HIGH or "1" at its output when any one of its inputs is HIGH is a(n):
How many NAND circuits are contained in a 7400 NAND IC?
Layer one of the OSI model is
What layer of OSI determines the interface of the system with the user?
What command is used to remove jobs from the print queue?
How can you navigate around virtual consoles?
Which of the following NIS clients, finds and stores information about an NIS domain and server?
The physical layer of a network
What TCP/IP protocol is used for remote terminal connection service?
How many networks and nodes per network, are allowed by the Class B network?
What service is used to translate domain names to IP addresses?
Which of the following command is used to create a Linux installation boot floppy?
How can you add Amit, a new user, to your system?
What file specifies the order in which to use specified name services?
How many primary partitions can exist on one drive?
In which directory can you store system user default files used for creating user directories?
How could you install the file ipchains-1.3.9-5.i386.rpm?
What does FSF stand for?
Which of the following is a valid format for mounting a CD-ROM drive?
What command do you use to create Linux file systems?
Which of the following command can you execute to count the number of lines in a file?
Which of the following is not a communication command?
What command is used to display the characteristics of a process?
What command is not used to list the files chap01, chap02 and chap04?
What command is used with vi editor to replace text from cursor to right
What sign is used to back up over typing errors in vi?
What sign is used to erase or kill an entire line you have typed and start you are on a new line (but not display a new prompt)?
What command is used to sort the lines of data in a file in alphabetical order?
What command is used with vi editor to save file and remain in the editing mode?
What command is used with vi editor to move back to the beginning of a word?
What command is used with vi editor to search a pattern in the forward direction?
What command is used to add printing jobs to the queue?
What protocol(s) is(are) allowed a user to retrieve her/his mail from the mail server to her/his mail reader?
What project is currently developing X server support?
What X-based tool is available for configuring the X Window system?
Which of the following server is used with the BIND package?
What port does squid listen, by default?
Which of the following is the main Apache configuration file?
Which of the following command is used to access an SMB share on a Linux system?
Which of the following command is used to see the services running in NFS server?
In which tcp_wrappers file can you specify to allow all connections from all hosts?
What does GNU stand for?
What shell's wild-card is used to match any number of characters including none?
What command is used to list contents of directories?
What command is used with vi editor to append text at end of line?
What command is used to copy directory structures in and out?
In OSI network architecture, the dialogue control and token management are responsible of
What command is used to count the total number of lines, words, and characters contained in a file?
What command is used to remove files?
What command is used to remove the directory?
What command is used with vi editor to delete a single character?
What hardware architectures are not supported by Red Hat?
What command can be used to get information about yourself?
What layer protocol is responsible for user and the application programme support such as passwords, resource sharing, file transfer and network management?
What package group will you select during the custom configuration to enable the machine to communicate with Windows clients?
Which of the following tool allows you to change your default X Window desktop?
What type of addressing format is used by Class A network.
What types of installations require a special boot disk?
RPM
What command is used to query for a specific package with RPM?
What script is run for setting bash global defaults for all users?
Who founded the Linux Kernel?
Which of the following is not a part of default Red Hat Linux email system?
_____ tool allows you to change your default X Window desktop.
In what file can you specify which users are not allowed to access a system via FTP?
Which program is used to schedule particular jobs or programs at particular times on the system?
Which command can force all buffers to disk?
How many extended partitions can exist on one drive?
For you to create a swap partition by using fdisk, what must the partition's system ID type be?
What file contains the list of port numbers (and associated names) monitored by inetd?
The location of some system configuration and system administrator executable files, is:
The location for subdirectories for local programs and executables for user and administrative commands, is:
Which of the following is not a filter command?
What command is used to display a file contents in octal form?
What command is used to assign executable permission to all of the files named "report"?
What command is used to change the working directory?
What command is used to count the number of files in the current directory by using pipes?
What command is used to count just the number of characters in a file?
How many class A, B and C network IDs can exist?
LILO
How can you rebuild the RPM file to include the new patches?
What command is used to set user and group quotas?
NIS
In order to increase the amount of memory available for a system, what is the maximum size of a swap partition (with kernel version 2.2.x)?
Which file is used to configure which filesystems are mounted?
Who has developed the Linux?
What does OSS stand for?
Which of the following subdirectory(ies) contains the device files?
Which of the following subdirectory(ies) contains the system boot scripts.
What of the following tool is used to check and repair Linux file systems?
Which of the following tool is used to partition your hard drive?
Where can system and mail logs be found in Ret Hat Linux?
What command is used to display and create files?
Which of the following command can be used to rename a file in UNIX?
What command is used to remove a file?
What command is used to display the top of the file?
What command is used to save the standard output in a file, as well as display it on the terminal?
What command is used to count just the number of lines contained in a file?
In OSI network architecture, the routing is performed by
The 32-bit internet address 10000000 00001010 00000010 00011110 will be written in dotted decimal notation as
Which class network is used for a collection of a small number of networks with a large number of nodes?
What TCP/IP protocol is used for file transfer with minimal capability and minimal overhead?
What TCP/IP protocol is used for transferring electronic mail messages from one machine to another?
What command is used to halt a Linux system?
Which daemon is used for the Apache server?
GNOME is based on
What can he used to set up a firewall on a Linux system?
Which program is used to automatically install Red Mat Linux on identical hardware?
What service is not monitored by inetd ?
Who founded the FSF?
What shell's wild-card is used to match a single character?
What command is used to copy a file?
What command is used to display your current working directory?
What command is used with vi editor to move the cursor to the left?
What command do you use to add routes to a Linux router?
Which of the following command is used to mount NFS filesystems?
To build a modularized kernel, the kernel-headers and kernel-source packages must first be installed. Where will you find the kernel-headers and kernel-source?
After you have compiled your kernel, what do you have to edit to boot your new kernel image?
To create an installation boot floppy disk from Linux (or another Unix) machine, what command could you use?