1. To avoid fading of signals especially in UHF or VHF transmission, this technique is used

increase antenna height
frequency diversity
increase power
use fixed antenna

2. Ratio of maximum deviation allowed to the modulating frequency is a

modulation ratio
frequency deviation
modulation deviation
modulation index

3. If the 10 KHz tone is transmitted,and the maximum deviation is 75 KHz, the modulation index is

750
75
7.5
0.75

4. Phase modulation is called

pulse code
direct FM
indirect FM
dual phase shift modulation

5. If the radiation resistance of the antenna is 50 ohms, the antenna current ampere, the radiated power is

250 W
10 W
1,250 W
1,250 KW

6. The most ideal SWR in VHF communications

infinite SWR
very high SWR
zero SWR
unity SWR or 1:1 SWR

7. What circuit device is used to suppress the carrier in SSB transmitter

wave trap
band-pass filter
suppressor circuit
balanced modulator

8. Deviced used for producing FM in a transmitter

balanced modulator
frequency modulator
reactance modulator
lock modulator

9. Second harmonic of 500 KHz is

1,000 KHz
10,000 KHz
250 KHz
1,500 KHz

10. If the radio wave is 10 meters long, the frequency is (use formula A=300/Frequency in MHz

300 MHz
600 MHz
30 MHz
3 MHz

11. Two forms of angle modulation are frequency modulation band

pulse
amplitude
space
phase modulation

12. F3 emission means carrier is

frequency modulated by on-off keying
frequency modulated by phase shifting
frequency modulated by voice
frequency modulated by direct/data keying

13. For HF or SSB propagation, frequency band used is

300-3,000 KHz
3-30 MHz
30-300 MHz
3-30 GHz

14. To overcome difficulty in spelling, the

phonetic alphabet
Q code
ten code
morse code

15. When it is 10:00 AM in the Philippines, what is it in UTC?

10 AM
0800
0200
0100 UTC

16. Which diodes are normally biased?

varactor
bi-polar
TRC
zener

17. The symbol used for current amplication factor of transistors is

alpha
beta
gamma
delta

18. A circuit element that opposes change in current

capacitor
inductor
resistor
conductor

19. Radiation occuring on frequencies which are whole multiple of the original desired frequency is called

spurious
harmonic
intermode
cross talk radiation

20. Undesired oscillation developed in a radio frequency amplifier circuit at some frequency higher than the normal operating frequency is called

sympathetic
spurious
parasitic
operational oscillations

21. Polarization of VHF whip antenna

circular
horizontal
vertical
dual polarization

22. A device used to remove one sideband from a double sideband signal

balanced modulator
reactance modulator
multi-vibrator
band pass filter

23. Ideal value of signal to noise ratio

unity
zero
infinity
very small

24. Frequency range between two half-power points is

beamwidth
bandwidth
frequency limits
beam angle

25. Root-mean-square (rms) value of a sine wave

50%
86.6%
70.7%
100%

Score = 

Correct answers: