from pinoy bix amplifiers

Question 1

which of the following is (are) power amplifiers

a. class a
b. class B or AB
c. class c or d
d. all of the above

Answer 1

all of the above

Question 2

by how much does the output signal signal vary for a class AB power amplifier

Answer 2

between 180• and 360•

Question 3

which type of amplifier is biased for operation at less that 180• of the cycle

Answer 3

Class C

Question 4

which type of amplifier uses pulse digital signals in its operation

Answer 4

class D

Question 5

which of the power amplifiers has the lowest overall efficiency

Answer 5

Class A

Question 6

which of the following describes a power amplifier
a. it can handle large power
b. it can handle large current
c. it does not provide much voltage gain
d. all of the above

Answer 6

all of the above

Question 7

amplifiers primarily provide sufficient power to an output load to drive a speaker from few watts to ten watts

Answer 7

power

Question 8

the main features of a large signal amplifier is the circuit’s
a. power efficiency
b. maximum power limitations
c. impedance matching to the output device
d. all of the above

Answer 8

all of the above

Question 9

Class AB operation is _____ operation
a. similar to class a
b. similar to class b
c. similar to class c
d. none of the above

Answer 9

none of the above

Question 10

which operation class is generally used in radio or communications

Answer 10

Class D

Question 11

Categorieze the power efficiency of each class of amplifier from worst to best

Answer 11

A,AB,B,D

Question 12

what is the maximum efficiency of a Class A circuit with a direct or series fed load connection?

Answer 12

25%

Question 13

what is the ratio of the secondary voltate to the primary voltage with the turn ratio in the winding?

Answer 13

N2/N1

Question 14

the maximum efficiency of a transformer coupled class a amplifier

Answer 14

50%

Question 15

what is the maximum efficiency of a class B circuit?

Answer 15

78.5%

Question 16

how many transistors must be used in a class b power amplifier to obtain the output for the full cycle of the signal

Answer 16

2

Question 17

Class B operation is provided when dc bias leaves the transistor biased just off, the transistor turning on when the ac signal is applied (true/false)

Answer 17

true

Question 18

which of the push pull amplifierd is presently the most popular form of the class b power

Answer 18

Quasi Complementary

Question 19

which of the following instruments displays the harmonic of a distorted signal

Answer 19

spectrum analyzer

Question 20

which of the folloeing instrument allows more precise measurement of the harmonic components of a distorted signal

Answer 20

wave analyzer

Question 21

maximum temp. rating for silicon power transistors

Answer 21

150• to 200•

Question 22

which power amplifier is not intended primarily for large signal or power amplification

Answer 22

Class C

Question 23

popular transistor driver device for class D amplification

Answer 23

MOSFET

Question 24

amplifier that has an output signal varies for a full 360 degrees of the cycle

Answer 24

class A

Question 25

Class B amplifieroutput signal varies of the cycle

Answer 25

180•

Question 26

highest overall efficiency amplifier

Answer 26

Class D

Question 27

Class D operation can achieve power efficiency of over

Answer 27

90%

Question 28

the beta of a power transistor is generally

Answer 28

less than 100

Question 29

First active satellite

Answer 29

Sputnik I

Question 30

First commercial satellite

Answer 30

Telstar

Question 31

first passive satellite transponder?

Answer 31

early bird

Question 32

First satellite to receive and transmit simultaneously

Answer 32

Telstar I

Question 33

A helical antenna is used for satellite tracking because of

Answer 33

circular polarization

Question 34

repeaters inside communications satellite are known as

Answer 34

Transponders

Question 35

considered unsolved problem in satellite system

Answer 35

privacy

Question 36

geographical representation of a satellite antenna radiation

Answer 36

footprint

Question 37

smallest beam of a satellite antenna radiation pattern

Answer 37

spot beam

Question 38

a satellite beam that covers almost 42.4% of the earths surface

Answer 38

global beam

Question 39

frequency range of C band

Answer 39

3.4 to 6.45 GHz

Question 40

a satellite signal transmitted from a satellite transponder to earth station

Answer 40

Downlink

Question 41

collects a very weak signal from broadcast satellite

Answer 41

Satellite Dish

Question 42

detects the satellite signal relayed from the feed and converts it to an electric current amplifies and lowers its frequency

Answer 42

LNA

Question 43

loss of power of a satellite downlink signal due to earth's atmosphere

Answer 43

path loss

Question 44

what height must a satellite be placed above the surface of the earth in order for its rotation?

Answer 44

22,426.4 miles

Question 45

point on the satellite orbits closest to the earth

Answer 45

perigee

Question 46

earth area covered by a satellite radio beam

Answer 46

foot print

Question 47

what is the local oscillator frequency of the satellite with an uplink frequency in GHz band

Answer 47

2225 MHz

Question 48

vsat was made available in

Answer 48

1979

Question 49

what band does vsat first operate

Answer 49

C band

Question 50

First Philippine Mabuhay satellite has how many channels

Answer 50

30

Question 51

The first philippine agila I will have how many transponder

Answer 51

36

Question 52

approximate path loss from satellite to earth station

Answer 52

200 dB

Question 53

INTELSAT

Answer 53

International Telecommunications Satellite

Question 54

a satellite cross link means

Answer 54

satellite to satellite link

Question 55

delay time for satellite transmission from earth transmitter to earth receiver

Answer 55

0.5 s

Question 56

as the height of a satellit3 orbit gets lower. the speed of the satellite

Answer 56

increases