Deck 1: Introductory Topics

Question 1

A popular, convenient way of representing noise calculations, mainly involved with microwave receivers, is:

A) Noise figure.
B) Equivalent noise resistance.
C) SIN ratio.
D) Equivalent noise temperature.

Answer 1

D

Question 2

The statement "information is proportional to bandwidth" is known as:

A) Fourier's Law
B) Simpson Rule
C) Shannon's Law
D) Hartley's Law

Answer 2

D

Question 3

A device that converts energy from one form to another is called a:

A) transmitter
B) detector
C) transducer
D) modulator

Answer 3

C

Question 4

Two types of noise that occur at extremely low and high frequencies in amplifiers containing transistors are known as:

A) Johnson noise and pink noise.
B) excess noise and transit time noise.
C) flicker noise and shot noise.
D) 1/f noise and thermal noise.

Question 5

Which is NOT a term for noise produced by resistors?

A) Thermal noise
B) Shot noise
C) Johnson noise
D) White noise

Question 6

The device which superimposes information onto a high frequency signal for transmission is called:

A) the carrier
B) a demodulator
C) a modulator
D) the intelligence

Question 7

A figure of merit that best describes how much noise a device creates is known as:

A) Noise figure.
B) Friis noise.
C) effective noise bandwidth.
D) signal to noise ratio.

Question 8

When using a noise diode generator in making noise measurements, the noise diode's current in ma. is numerically equal to the:

A) noise ratio of the DUT only if its impedance is 50 ohms.
B) noise figure in decibels of the DUT only if its impedance is 50 ohms.
C) noise ratio of the DUT no matter what its impedance is.
D) noise figure in db of the DUT no matter what its impedance is.

Question 9

In a three-stage amplifier.

A) the noise ratio of the last stage is usually insignificant.
B) Friss's formula can be used to determine the overall noise effect of all three stages.
C) the noise ratio of all three stages is mainly due to the noise figure of the first stage.
D) all of the above

Question 10

Which is NOT an example of internal noise?

A) Excess noise
B) Noise produced by transistors and integrated circuits
C) Noise produced by resistors
D) Space noise

Question 11

Determine the frequency of a Clapp oscillator if L4 = 35 mH and C3 = 20pf.

A) 200 kHz
B) 20 kHz
C) 1.9 MHz
D) 190 kHz

Question 12

A transistor amplifier has a measured S/N power of 25 at its input and 8 at its output. Its noise figure in decibels is:

A) 9.10
B) 118
C) 17
D) 4.95

Question 13

The type of noise that is often produced by spark producing equipment is known as:

A) thermal noise.
B) transistor noise.
C) man made noise.
D) atmospheric noise.

Question 14

A technique for resolving complex repetitive waveforms into sine or cosine waves and a dc component is known as:

A) Frequency Analysis
B) Fourier Analysis
C) Armstrong's Principle
D) Harmonic Analysis

Question 15

Ultra High Frequency signals are between:

A) 30 Mhz and 300 MHz.
B) 300 Mhz and 3 GHz.
C) 3 Mhz and 30 MHz.
D) 3 Mhz and 30 GHz.

Question 16

The device which extracts the information signal from the high frequency carrier in a receiver is called a:

A) demodulator
B) transducer
C) modulator
D) transmitter

Question 17

If the noise produced by a resistor in a radio receiver is 2.4 uV and the resistance is then doubled, the resulting noise produced by the new resistance is approximately:

A) 4.8 uV
B) 2.4 uV
C) 3.4 uV
D) 1.2 uV

Question 18

Given that a filter has a Q of 50 and a BW of 500 Hz, determine its resonant or center frequency

A) 2500 kHz
B) 100 kHz
C) 25,000 kHz
D) 250 kHz

Question 19

Frequencies between 3 and 30 Mhz are referred to as:

A) Very High Frequencies (VHF').
B) High Frequencies (HF).
C) Medium Frequencies (MF).
D) Ultra High Frequencies (UHF')

Question 20

Shot noise is directly related to:

A) resistor value
B) ac voltage
C) Boltzman constant
D) dc current

Question 21

Convert 300W to dBW

A) -10.0 dBW
B) 54.77 dBW
C) -24.77 dBW
D) 24.77 dBW

Question 22

Determine the voltage level required to produce a +10dBm level. Assume a 600 Ohm system

A) )775V
B) 2.45V
C) 1.947V
D) none of the above

Question 23

The repetitive exchange of energy from the magnetic field of an inductor to an electric charge on a capacitor in a resonant circuit is known as:

A) the piezoelectric effect
B) Barkhausen criteria
C) the flywheel effect
D) frequency synthesis

Question 24

The oscillator design that uses two capacitors in the tank circuit is the:

A) Clapp design
B) Colpitts design
C) Crystal design
D) Hartley design

Question 25

The main requirements that must be met for an oscillator to successfully oscillate are known as:

A) the flywheel effect
B) the piezoelectric effect
C) Barkhausen criteria
D) frequency synthesis

Question 26

A 4.7 mH inductor has a Q of 3500 at a frequency of 50 MHz. Its internal resistance is approximately:

A) 2.37 milliohms.
B) 67.14 ohms.
C) 14.9 milliohms.
D) 422 ohms.

Question 27

The oscillator design that has the highest frequency stability is the:

A) Hartley design
B) Clapp design
C) Crystal design
D) Colpitts design

Question 28

Hartley's law states that:

A) amount of information is directly proportional to both the system bandwidth and time of transmission.
B) the time of transmission is directly proportional to both the system bandwidth and the amount of information.
C) the bandwidth is directly proportional to both the amount of information and the amount of noise present.
D) bandwidth is directly proportional to both the amount of information and time of transmission.

Question 29

A square wave is made up of a summation of:

A) rectangle waves
B) ramps
C) sinusoids
D) pulses

Question 30

A measured value of 10mW will result in what dBm power level?

A) -3dBm
B) 0dBm
C) 10dBm
D) 3dBm

Question 31

A laser diode outputs +8 dBm. Convert this value to Watts

A) 0.0063W
B) 0.063W
C) 0.00063W
D) 0.63W

Question 32

The oscillator design that is characterized by having a "tapped" inductor is the:

A) Colpitts design
B) Clapp design
C) Crystal design
D) Hartley design