Countdown Timer: 2 weeks 5 days to go
Right, onto one of those subjects I have not covered in much detail - measurements.
Which one of the following is an essential characteristic of a diode for use in a probe to measure RF?
a) A high current capacity
b) A low internal capacitance
c) A screened outer coating
d) A high peak inverse voltage (PIV)
The correct answer is b) A low internal capacitance.
Which of the following instruments can be used to detect the presence of harmonics?
a) Analogue multimeter
c) Absorption wavemeter
d) Digital counter
The correct answer is c) Absorption wavemeter.
What name is given to a resistor wired in series with a milliammeter to measure voltage?
a) Shunt resistor
b) Parallel resistor
c) Limiter resistor
d) Multiplier resistor
The answer is d) Mutiplier resistor.
A heterodyne wavemeter consists of an absorption wavemeter and a
a) frequency counter
b) SWR meter
c) digital readout
d) crystal oscillator
The answer is d) crystal oscillator.
What sort of voltage is applied to the horizontal deflection plates of an oscilloscope to produce the timebase?
The correct answer is a) ramp.
When using an absorption frequency meter, a DC power source is connected
a) to the circuit being tested but NOT to the absorption frequency meter
b) to BOTH the circuit being tested AND to the absorption frequency meter
c) NEITHER to the circuit being tested NOR to the absorption frequency meter
d) to the absorption frequency meter but NOT to the circuit being tested
The correct answer is a) to the circuit being tested but NOT to the absorption frequency meter.
A resistor wired across the terminals of a milliammeter to enable it to measure a higher current is known as a
a) expanding resistor
b) current shunt
d) series resistor
The correct answer is b) current shunt.
Which one of the following is a disadvantage from which an absorption frequency meter suffers?
a) Low sensitivity
b) High cost
c) It only responds to DC
d) Its power supply must be stable.
The answer is a) Low sensitivity.