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Worksheets

EST 12

Total questions: 50

Worksheet time: 25mins

Name
Class
Date
1.

What is the period of a wave?

a)

The number of degrees in tone cycle

b)

The number of zero crossing in one cycle

c)

The amplitude of the wave

d)

The time required to complete one cycle

2.

Is the total useful information processed or communicated over a specific amount of time

a)

Baud rate

b)

Bit rate

c)

Information theory

d)

Throughput

3.

What is the approximate percentage of earth coverage of a geostationary satellite at zero degree elevation?

a)

33.3%

b)

45.2%

c)

42.5%

d)

30.5%

4.

This refers to an area in the memory used for temporary storage of information on the basis of “Last in First out”.

a)

Core

b)

Register

c)

Flag

d)

Stack

5.

What is a driven element of an antenna?

a)

Always the rearmost element

b)

Always the forward most element

c)

The element fed by the transmission line

d)

The element connected to the rotator

6.

Which of the following term best described the overload distortion?

a)

Peak limiting

b)

Quantization noise

c)

Granular noise

d)

Slope distortion

7.

What do you mean by the outward flow of and energy from any source in the form of radio waves?

a)

Radiation

b)

Emission

c)

Encoding

d)

Tracking

8.

Refer to the deviation of the operating frequency of a crystal oscillator from its nominal value due to temperature variations.

a)

Drift

b)

Flash over

c)

Frequency deviation

d)

Deviation ratio

9.

Find the product of the following binary number 100 to 101.

a)

11000

b)

10100

c)

10010

d)

11100

10.

Which of the following is and impedance matching ration of coax balun?

a)

2:8

b)

1:2

c)

4:1

d)

2:1

11.

Quantity that do not change when a beam of light enters on e medium to another.

a)

Frequency

b)

Wavelength

c)

Direction

d)

Speed

12.

Which of the following described the very early standard that defines binary digits as space/mark line condition and voltage levels?

a)

V.4

b)

V.2

c)

V.1

d)

V.5

13.

A form of single sideband emission where the degree of carrier suppression enable the carrier to be reconstituted and be used for demodulation.

a)

Half carrier single sideband emission

b)

Full carrier single sideband emission

c)

Reduced carrier single sideband emission

d)

Double sideband emission

14.

An instrument for recording waveforms of audio frequency.

a)

Oscilloscope

b)

Phonoscope

c)

Radioscope

d)

Audioscope

15.

How much is the required minimum power output of an international AM BC stations?

a)

5 kW

b)

30 kW

c)

10 kW

d)

50 kW

16.

What is the equivalent of decimal 51 in binary?

a)

111011

b)

110011

c)

111001

d)

100011

17.

100011

a)

Iridium system

b)

Plutonium system

c)

Indium system

d)

Gallium system

18.

What do you call a circuit that controls the magnetron output?

a)

Inverter

b)

Impeller

c)

Modulator

d)

Converter

19.

Known as the satellite transmitted signal form a satellite transponder to earth’s station.

a)

Uplink

b)

Down link

c)

RHCP

d)

Vertically polarized

20.

Which of the following colors of light rays has the shortest wavelength?

a)

Yellow

b)

Violet

c)

Red

d)

Blue

21.

Antenna which is not properly terminated

a)

Isotropic

b)

Non-resonant

c)

Whip

d)

Resonant

22.

Term in communication which is referred, “to send out in all direction”.

a)

Announce

b)

Broadcast

c)

Transmit

d)

Media

23.

At the ends of a half-wave antenna, what values of current and voltage exist compared to the remainder of the antenna?

a)

Minimum voltage and minimum current

b)

Equal voltage and current

c)

Minimum voltage and maximum current

d)

Maximum voltage and minimum current.

24.

One of the following stands for SONET acronym in telecommunication

a)

System optical network

b)

Simple operation network

c)

Synchronous optical network

d)

System operating network

25.

How can intermodulation interference between two transmitters in close proximity reduced or eliminated?

a)

Through installing a band-pass filter in the antenna feed line

b)

Through installing terminated circulator or ferrite isolator in the feed line of the transmitter and duplexer

c)

By using a class C final amplifier with high driving power

d)

By installing a low-pass filter in the antenna feed line

26.

What propagation condition is usually indicated when a VHF signal is received from a station over 5000 miles away?

a)

Moonbounce

b)

D-layer absorption

c)

Tropospheric ducting

d)

Faraday rotation

27.

In radio High frequency communications the higher the radio frequency the ______.

A. Higher it can

a)

Higher it can reach

b)

Shorter it can reach

c)

Effect is null

d)

Longer it can reach

28.

The signal to noise ratio that is required for a satisfactory television reception.

a)

. 30 dB

b)

40 dB

c)

10 dB

d)

20 dB

29.

What is meant by referring to electromagnetic waves as horizontally polarized?

a)

The electric field is parallel to the earth

b)

Both the electric and magnetic fields are vertical

c)

Both the electric and magnetic fields are horizontal

d)

The magnetic fields is parallel to the earth

30.

What is emission F3F?

a)

Facsimile

b)

Modulated CW

c)

RTTY

d)

Television

31.

How can receiver desensitizing be reduced?

a)

Increase the receiver bandwidth

b)

Ensure good RF shielding between the transmitter and receiver

c)

Increase the transmitter audio gain

d)

Decrease the receiver squelch, gain.

32.

Circuit used to amplify the optical signal in fiber optics communications links.

a)

Attenuator

b)

Optical repeater

c)

Optical amplifier

d)

Generator

33.

What do you call the single booster installed on the antenna dish of satellite receiver?

a)

Low noise amplifier

b)

Single amplifier

c)

Noise amplifier

d)

Rectifier

34.

Term for the transmission of printed pictures by radio?

a)

Facsimile

b)

ACSSB

c)

Xerography

d)

Television

35.

An interfering current in a telegraph or signaling channel due to telegraph or signaling current by another channel.

a)

Crosstalk

b)

Noise current

c)

Crossfire

d)

Intermodulation

36.

Where is the noise generated that primarily determines the signal-to-noise ratio in a VHF (150 MHz) marine-band receiver?

a)

In the ionosphere

b)

In the receiver rear end

c)

In the receiver front end

d)

In the atmosphere

37.

Known as the data transfer scheme that used handmaking principle.

a)

Synchronous data transfer scheme

b)

DMA data transfer scheme

c)

Asynchronous data transfer scheme

d)

Uninterrupted data transfer scheme

38.

Type of modulation used in TV broadcast visual transmitter.

a)

Pulse modulation

b)

DSBFC

c)

Vestigial sideband

d)

SSBFC

39.

A transmitter supplies 8 kW to the antenna when it is unmodulated, determine the total radiated power when modulated at 30%.

a)

5 kW

b)

20 kW

c)

15 kW

d)

8.36 kW

40.

Best describe as an amplifier used in radio telephony.

a)

Magnifier

b)

Class B

c)

Class C

d)

Class A

41.

The latest government regulation in the telecommunication which provides policy for the provision of local exchange carrier service.

a)

E.O. 546

b)

E.O. 109

c)

Act 3948

d)

E.O. 59

42.

Referred to as the stage in the radio receiver that contributes most of the noise.

a)

IF amplifier

b)

Supply stage

c)

Speaker

d)

Mixer

43.

The frequency tolerance of an AM radio broadcast station

a)

200 Hz

b)

2000 Hz

c)

20 Hz

d)

2 Hz

44.

What are electromagnetic waves?

a)

A wave consisting of two magnetic fields at right angles to each other

b)

A wave consisting of an electric field and a magnetic field at right angles to each other.

c)

Alternating currents in the core of an electromagnet

d)

A wave consisting of two electric fields at right angles to each other

45.

What is the frequency range of C-band?

a)

10.95 to 14.5 GHz

b)

27.5 to 31 GHz

c)

3.4 to 6.424 GHz

d)

1.53 to 2.7 GHz

46.

Determine from the following the basic mode of transmission system in the public data network in which data are transferred from the source to the network and from the network to the destination in the frame format.

a)

Voice mode

b)

Asynchronous mode

c)

Synchronous mode

d)

Packet mode

47.

Refers to a type of beam antenna which uses two or more straight elements arranged in line with each other.

a)

Dipole antenna

b)

Yagi antenna

c)

Whip antenna

d)

Rhombic antenna

48.

What is a frequency discriminator?

a)

A circuit for filtering two closely adjacent signals

b)

A circuit for detecting FM signals

c)

An FM generator

d)

An automatic bandswitching circuit.

49.

These are used to connect non-ISDN equipment of ISDN line.

a)

Digipeaters

b)

Terminal adapters

c)

Local repeaters

d)

Terminal repeaters

50.

The executive branch of government in charge of policy making in the telecommunications.

a)

National telecommunications commission

b)

Telecommunications control bureau

c)

Department of transportation and communications

d)

Bureau of telecommunications