Quiz V6.0 Electronics and Radio. 10 Questions.
Credits to: JimB
Attempt All Questions.
| Q1:The frequency of a radio signal is 152.5Mhz, what is the approximate wavelength? |
| Q2: A 100Mhz sinewave is amplitude modulated (modulation depth is 50%) with a 15khz square wave.
If we look at the resulting signal with a spectrum analyser, we will see individual components at:|
100Mhz and 15khz only
100Mhz, 100.015Mhz, 100.045, 100.075, 99.985, 99.955, 99.925 and some other frequencies
You cannot use AM at 100Mhz, only FM.
| Q3: A superheterodyne radio receiver, with an intemediate frequency of 450khz is tuned to receive a signal on 2200khz.
It also receives an unwanted signal on 2.650Mhz.
This problem is due to:|
Poor image rejection
Local oscillator drift
| Q4: The practical bandwidth required for a frequency modulated signal is given by the expression BW = 2 x (deviation + highest modulating frequency).
This is known as:|
The expression is wrong
| Q5: A 50Mhz radio transmitter is designed to output 10 watts of RF into a 50 ohm load.
A single wire antenna 3metres long is connected directly to the antenna socket.
The transmitter will:|
Transmit a stronger signal because the antenna is longer than required
Transmit a weaker signal because the antenna is shorter than required
Operate in an undefined manner
| Q6: An amplifier has a gain of 20dB, the input and output impedances are the same,
What is the voltage gain of this amplifier:|
| Q7: The Q of a coil refers to: |
The number of turns
The resistance of the wire
The ratio of resistance and reactance
| Q8: A 20Mhz tuned circuit has a Q of 100.
The 3dB bandwidth will be: |
Dont know, depends if it is series or parallel tuned
| Q9: The range of a 200mW 450Mhz handheld radio is:|
10km or more
Depends on the height of the radios at each end of the link.
| Q10: In order to correctly receive a single sideband suppressed carrier signal, a receiver must have:
A narrow IF filter
A Beat Frequency Oscillator (BFO) or Carrier Insertion Oscillator (CIO)
A low distortion audio amplifier