Start Practice Exam Test Questions
Choose the letter of the best answer in each questions.
1. One of the following types of noise becomes of great importance at high frequencies. It is the
- a. shot noise
- b. random noise
- c. impulse noise
- d. transit-time noise
2. Indicate the false statement.
- a. HF mixers are generally noisier than HF amplifiers.
- b. Impulse noise voltage is independent of bandwidth.
- c. Thermal noise is independent of the frequency at which it is measured.
- d. Industrial noise is usually of the impulse type.
3. The value of a resistor creating thermal noise is doubled. The noise power generator is therefore
- a. halved
- b. quadrupled
- c. doubled
- d. unchanged
4. One of the following is nota useful quantity for comparing the noise performance of receivers:
- a. Input noise voltage
- b. Equivalent noise resistance
- c. Noise temperature
- d. Noise figure
5. Indicate the noise whose source is in a category different from that of the other three.
- a. Solar noise
- b. Cosmic noise
- c. Atmospheric noise
- d. Galactic noise
6. Indicate the false statement. The square of the thermal noise voltage generated by a resistor is proportional to
- a. its resistance
- b. its temperature
- c. Boltzmann’s constant
- d. the bandwidth over which it is measured
7. Which of broad classifications of noise are most difficult to treat?
- a. noise generated in the receiver
- b. noise generated in the transmitter
- c. externally generated noise
- d. internally generated noise
8. Space noise generally covers a wide frequency spectrum, but the strongest interference occurs
- a. between 8 MHz and 1.43 GHz
- b. below 20 Mhz
- c. between 20 to 120 MHz
- d. above 1.5 GHz
9. When dealing with random noise calculations it must be remembered that
- a. all calculations are based on peak to peak values
- b. calculations are based on peak values
- c. calculations are based on average values
- d. calculations are based on RMS values
10. Which of the following is the most reliable measurement for comparing amplifier noise characteristics?
- a. signal-to-noise ratio
- b. noise factor
- c. shot noise
- d. thermal noise agitation
11. Which of the following statements is true?
- a. Random noise power is inversely proportional to bandwidth
- b. Flicker is sometimes called demodulation noise
- c. Noise is mixers is caused by inadequate image frequency rejection
- d. A random voltage across a resistance cannot be calculated