ESAT COACHING 1

A digital filter:

The following are the advantages of digital filter except:

A digital filter in its simplest form consists of

Digital filter has an accuracy that depends on:

An analog filter:

The following are the advantages of analog filters except:

Analog filter has an accuracy that depends on:

Which of the following are the 2 fundamental types of digital filter?

FIR means:

IIR means:

A digital filter system that has finite duration unit sample response. I.e h(n)=0 for n<0 ad n>M. Thus the unit sample response exists for the duration of 0 to M-1.

A digital filter system that are non-recursive. Thus the output of this filter depends upon present and past inputs.

A digital filter system that has infinite duration unit sample response. I.e h(n)=0 for n<0. Thus the unit sample response exists for the duration of 0 to ∞.

A digital filter system that are recursive. Thus feedback is used and the output of this filter depends upon present and past inputs as well as the past outputs.

Frequency and ____ are the inverse of each other.

Frequency is the rate of change with respect to _____

Change in a short span of time means ______

Change over a long span of time means _______

If a signal does not change at all, its frequency is ______

If a signal changes instantaneously, its frequency is _______

Phase describes the position of the waveform relative to time _____

A single-frequency data sine wave is not useful in communications; we need to send a composite signal or _______

The bandwidth of a composite signal is the difference between the _____

In baseband transmission, the required bandwidth is proportional to the___:

In baseband transmission, if we need to send bits faster, we need _____ bandwidth.

Which of the following is true if the available channel is a bandpass channel?

If we cannot send the digital signal directly to the bandpass channel, then

Increasing the levels of a signal may _____ the reliability of the system.

The Shannon capacity gives us the _____.

The Nyquist formula tells us:

In networking, we use the term bandwidth in two contexts. The first, bandwidth in hertz, refers to:

In networking, we use the term bandwidth in two contexts. The second, bandwidth in bits per second refers to:

The ____ defines the number of bits that can fill the link.

The actual bandwidth of a digital signal is ____.

The effective bandwidth of a digital signal is _____.

An NRZ where the level of the voltage determines the value of the bit.

An NRZ where the inversion or the lack of inversion determines the value of the bit.

NRZ-L and NRZ-I both have an average signal rate of _____.

Which have a DC component problem.

In Manchester and differential Manchester encoding, the transition at the middle of the bit is used for _____.

The minimum bandwidth of Manchester and differential Manchester is:

In bipolar encoding, we use _____ levels:

The three levels in bipolar encoding are:

In mBnL schemes, a pattern of m data elements is encoded as a pattern of n signal elements. Which is true?

Block coding is normally referred to as ____ coding;

BSZS substitutes eight consecutive zeros with _____.

HDB3 substitutes four consecutive zeros with _____ depending on the number of nonzero pulses after the last substitution.

According to the Nyquist theorem, the sampling rate must be:

In asynchronous transmission, start bit is:

In asynchronous transmission, stop bit is:

In asynchronous transmission, we send ___ start bit (0) at the beginning and stop bit/s (1) at the end of each byte.

In asynchronous transmission, the byte level is:

In asynchronous transmission, the bit level is:

In asynchronous transmission, the byte level and the bit level synchronization duration:

In synchronous transmission, we send bits one after another:

In synchronous transmission, it is the responsibility of the ______ to group the bits.

The number of bits per second.

The number of signal elements per second.

In the analog transmission of digital data, the baud rate is _____ to the bit rate.

A combination of ASK and PSK.

The total bandwidth required for AM can be determined from the bandwidth of the audio signal:

The total bandwidth required for FM can be determined from the bandwidth of the audio signal:

The total bandwidth required for PM can be determined from the bandwidth and maximum amplitude of the modulating signal:

It is the wise use of available bandwidth to achieve specific goals.

Efficiency can be achieved by_______.

Privacy and antijamming can be achieved by _______.

An analog multiplexing technique that combines analog signals.

An analog multiplexing technique that combines optical signals.

It is a digital multiplexing technique for combining several lowrate channels into one high-rate one.

In _______, the data rate of the link is n times faster, and the unit duration is n times shorter.

Radio waves are used for:

Microwaves are used for:

Radio waves are used for multicast communications, such as:

Microwaves are used for unicast communication such as:

This can be used for short-range communication in a closed area using lineof-sight propagation.

The science of sound.

The angle between the incident wave and the normal.

The angle between the normal and the path of a wave through the second medium.

The property of a radiator to emit strong radiation in one direction.

A horizontal, long-wire antenna designed for reception and transmission of low-frequency, vertically polarized ground waves.

An array in which the direction of maximum radiation is perpendicular to the plane containing the elements

The ratio of voltage to current at any given point on a transmission line. Represented by a value of impedance.

An antenna array with all the elements in a straight line where the maximum radiation is perpendicular to the axis of the elements.

The colors of light produced when two of the primaries are mixed in overlapping beams of light.

The complementary colors of light are:

Longitudinal waves that have been compressed (made more dense) as they move away from the source.

Another term for DRIVEN ARRAY.

A half-wave antenna with a reflector consisting of two flat metal surfaces meeting at an angle behind the radiator.

A coupling coil that connects the transmitter to the feeder.

The maximum angle at which radio waves can be transmitted and still be refracted back to earth.

Another name for antenna CENTER-FEED METHOD.

One complete alternation of a sine wave that has a maximum value above and maximum value below the reference line.

The compactness of a substance or mass per unit volume.

The heating of an insulating material by placing it in a high frequency electric field.

The bending of the paths of waves when the waves meet some form of obstruction.

A common type of half-wave antenna made from a straight piece of wire cut in half. Each half operates at a quarter wavelength of the output.

The parasitic element of an array that reinforces energy coming from the driver toward itself.

The refraction of light waves that causes the different frequencies to bend at slightly different angles.

The apparent change in frequency or pitch when a sound source moves either toward or away from a listener

An array in which all of the elements are driven.

The combination of an electric (E) field and a magnetic (H) field.

The radiation of radio waves into space.

A part of an antenna that can be either an active radiator or a parasitic radiator.

An array in which the direction of radiation is parallel to the axis of the array.

A transmission line that carries energy to the antenna.

A coaxial line made with a flexible inner conductor insulated from the outer conductor by a solid, continuous insulating materiaI.

The reflection of the original sound wave as it bounces off a distant surface

An array in which all of the elements are driven.

An array with three parasitic elements and one driven element.

The number of cycles that occur in one second. Usually expressed in Hertz.

The ratio of the energy radiated in the principal direction to the energy radiated in the opposite direction.

The ratio between the amount of energy propagated from an antenna that is directional to the energy from the same antenna that would be propagated if the antenna are not directional.

The portion of a groundplane antenna that acts as ground.

The loss of rf energy each time a radio waves is reflected from the Earth's surface.

Radio waves that travel near the surface of the Earth.