2. b it the beez practice 0

transcript

EASYMATHEMATICS

He was known as the father of modern geometry

ANSWER

Euclid

EASYEST

a flat conductor separated by an insulating dielectric from a large ground plane that is usually one-quarter or one-half wavelength long

ANSWER

microstrip

EASYEST

One complete revolution around a Smith Chart represents _________ wavelengths.

ANSWER

EASYMathematics

These are circles that have the same center.

ANSWER

concentric circles

EASYCommunication

The modulated peak value of a signal is 125V and the unmodulated carrier value is 85V. What is the modulation index?

ANSWER

EASYCommunication

A mismatched transmission line is also referred to as a ___________ line.

ANSWER

resonant

EASYCommunications

It is the ratio of the speed of propagation on a line to that of light in free-space.

ANSWER

velocity factor

EASYElectronics

Which of the following is the most widely used UTP cable that can carry baseband data at rates up to 100 Mbps at a range up to 100m?

ANSWER

EASYGEAS

This component measures the pulling (or pushing) action perpendicular to the section

ANSWER

Axial forces

EASYGEAS

It is the point at which there is an appreciable elongation of the material without any corresponding increase of load

ANSWER

Yield point

average

averageCOMMUNICATION

Determine the phase-shift represented by a 75 ns delay of a 4 MHz signal to a 75-ft cable with a dielectric constant of 2.3.

ANSWER

108 degrees

average

EASYSOLUTION

Θ = 360 td / T T =1/f = 1 / 4MHz = 250 ns Θ = 360 (75) / 250 = 108 degrees

average

EASYEST

The input to an FM receiver has a S/N of 2.8. What is the frequency deviation caused by the noise if the modulating frequency is 1.5KHz and the permitted deviation is 4KHz?

average

ANSWER

547.8 Hz

average

EASYSolution

= fm f= sin -1 N/S f= sin -1 1/2.8 f= 0.3652 = (0.3652)(1.5KHz) = 547.8 Hz

average

EASYEST

What circuit is used to return the frequency response of a signal to its normal, “flat” level?

average

ANSWER

de-emphasis

average

EASYMathematics

Let k be the number of gallons of a 50% silver nitrate solution that are added to 15 gallons of a 30% silver nitrate solution to produce a 35% silver nitrate solution. Let w be the number of sides of a regular polygon whose degree measure of one of the exterior angles is 8. Find the value of (k+w).

average

ANSWER

average

EASYMathematics

In how many distinct points do the real graphs of

Intersect?

average

ANSWER

average

EASYGEAS

It is the maximum safe stress that a material can carry

average

ANSWER

working stress

average

EASYCommunications

It is the most common means of overcoming the problems of quantizing error and noise.

average

ANSWER

companding

average

Electronics

It can be used in a single-stage oscillator circuit to provide a pulse signal suitable for digital-circuit applications.

average

ANSWER

UJT or unijunction transistor

average

averageGEAS

A large pipe, called a penstock in hydraulic work, is 1.5 m in diameter. It is composed of wooden staves bound together by steel hoops, each 300 sq. Millimetre in cross-sectional area, and is used to conduct water from a reservoir to power a house. If the maximum tensile stress permitted in the hoops is 130 MPa, what is the maximum spacing between hoops under a head of water of 30 m?

AVErage

ANSWER

L = 177 mm

AVErage

SOLUTION

(1000)(9.81)(30)(1.5)L = 2(300x10^-6)(130x10^6)L = 177 mm

averageGEAS

At what angular velocity will the stress in a rotating steel ring equal to 150 MPa if its mean radius is 220 mm? The density of the steel is 7.85 Mg/m^3.

AVErage

ANSWER

628 rad/s

AVErage

ANSWER

ω = (1/0.22)(150x10^6 / 7850)^(1/2) ω = 628 rad/s

Difficult

difficultCOMMUNICATION

It means that the characteristics and performance of an antenna are the same whether the antenna is radiating or intercepting an electromagnetic signal.

ANSWER

antenna reciprocity

difficult

EASYEST

Which of the following methods is used to lower the resonant frequency of a shortened vertical antenna?

difficult

ANSWER

top hat loading

difficult

EASYEST

Calculate the gain (relative to an isotropic) of a parabolic antenna that has a diameter of 3 m, an efficiency of 60% and operates at a frequency of 4 GHz.

difficult

ANSWER

39.8 dBi

difficult

EASYSOLUTION

G = 2 D2/ 2

= 3x108/ 4MHz = 0.075 m

G = 0.62(3)2

0.0752

G= 9474.8 G = 10 log 9474.8G = 39.8 dBi

difficult

EASYMathematics

Team A and B play a series of games. The first to win two games wins the series and Team A has a 70% chance of winning any game. What is the probability that Team A wins the series?

difficult

ANSWER

difficult

EASYMathematics difficult

ANSWER

difficult

EASYCommunication

It is a phenomenon caused by any support insulators used at the ends of the wire antenna.

difficult

ANSWER

end effect

difficult

EASYElectronics difficult

ANSWER

16.2 Hz

difficult

EASYSOLUTION

difficult

EASYGEAS

A pipe carry steam at 3.5 MPa has an outside diameter of 450 mm and a wall thickness of 10 mm. A gasket is inserted between the flange at one end of the pipe and a flat plate use to cap the end. How many 40-mm-diameter bolts must be used to hold the cap on if the allowable stress in the bolts is 80 MPa, of which 55 MPa is the initial stress?

difficult

ANSWER

N = 17

difficult

SOLUTION

N = (3.5x10^6)(0.45 – 2x0.01)^2 / [(0.04^2)(88–55)x10^6] N= 16.18 round upN = 17

difficult

DifficultGEAS

A pipe carry steam at 3.5 MPa has an outside diameter of 450 mm and a wall thickness of 10 mm. A gasket is inserted between the flange at one end of the pipe and a flat plate use to cap the end. What circumferential stress is developed in the pipe?

Difficult

ANSWER

= 75.3 MPa

Difficult

SOLUTION

σ = (3.5)(450 – 2x10) / [2(10)] = 75.3 MPa

DifficultGEAS

A steel rod having a cross-sectional area of 300 sq. Meters and a length of 150 m is suspended vertically from one end. It supports a tensile load of 20 kN at the lower end. If the unit mass of steel is 7850 kg/m^3 and E = 200x10^3 MN/m^2, find the total elongation of the rod.

Difficult

Answer

δ = 54.3 mm

Difficult

ANSWER

δ = [(7850)(9.8)(150^2) / 2(200X10^9)] + [(20000)(150)(1000^2) / 300(200X10^9)]

δ = 54.3 mm

2. b it the beez practice 0

Engineering