F-exam issues

This page addresses some of the F (and N) class issues which you may find in the the Dutch ham radio exam.
With thanks to Niek Hilbers of the Dutch VERON ham radio club. It helped me to pass my exam with success.

Here is some of the home-work we were given (still N level):
1.
U_in = 200 V_eff
C = 4700 µF
N1 = 1000 wdgs
N2 = 100 wdgs

What is the value of U (onloaded)?

A. ± 2,800 V B. ± 2,000 V C. ± 20 V D. ± 28 V

2. What is the right formula for frequency:

A. f = T/1 B. f = 2ΠR C. f = 1/T

3.
U_AB = ?

A. 0 V B. 1 V C. 2 V D. 3 V

4.
This is an amplifier with:

A. High voltage amplification

B. Voltage amplification with value = 0

C. Low voltage amplification

5.
This configuration is a:

A. mixing circuit

B. high frequency amplifier

C. oscillator

D. modulator

6.
Which transistor conducts?

A.
B.
C.
D.

7.
What is the maximum allowable current?
A. 25 mA
B. 40 mA
C. 200 mA

8.
Current I is:

A. 0 Amp
B. 1 Amp
C. 2 Amp
D. 4 Amp

9.
Which symbol represents a current source:

A, B, C or D

10.
The screen grid voltage -U_g is calculated with the following formula:

A. I_g * R_L .
B. U_a / R_a .
C. U_a / (R_a+R_k) .
D. I_a * R_k .

11.
A 16 kHz analogue sound should be sampled using a sample frequency of:

A. 34 kHz B. 25 kHz C. 16 kHz D. 8 kHz.

12.
Quantization noise is caused by:

A. rapid variation of signals B. square waves C. slow variation of signals.

13.
This number: 110011 represents:

A. binaire code B. analogue code C. hexadecimal code D. 6 tone code.

14.
Which mode of modulation is truly digital?

A. AM B. CW C. BPSK D. FSK

15. Ohm's law. Some elementary questions. Chapter 1. in the F book from the VERON.

What is correct?

a. The voltage is propotional to the current and the resistance.

b. The resistance is proportional to the voltage and inversely proportional to the current

c. The resistance is inversely proportional to the voltage and proportional to the current

d. The resistance is inversely proportional to the current and the voltage.

16.

a. 10 Amp.

b. 2 Amp.

c. 1.5 Amp.

d. 0 Amp.

17.

a. 8 Ω

b. 4 Ω

c. 2 Ω

d. 0.5 Ω

18.

The 'unit' for energy is?

a. Volt; b. watt; c. watt/sec.; d. Joule

19.

40 milliwatt is:

a. 0.004 Watt; b. 0.04 Watt, c. 0.4 Watt; d. 4 Watt

20.

a. ½ x

b. 2 x

c. 4 x

d. remains the same.

21.

U₁ = 4 V.; U₂ = 8 V. In resistor R is 4 Watt being dissipated.
When S is switched, how much Watt is than dissipated in R ?

a. 1 W
b. 2 W
c. 8 W
d. 16 W

22.

a. 10 V

b. 9 V

c. 1 V

d. 0 V

23.

What is the short-circuit current in the above picture ?

a. infinite b. 10 A c. 9 A d. 1 A

24.

a. 5 A

b. 3.5 A

c. 2 A

d. 1 A

25.

What is the unit of electric charge ?

a. Φ b. Ampère c. Coulomb d. Joule

26.

A battery of 40 Ah is being discharged in 10 hours. The average current was:

a. 400 A b. 40 A c. 4 A d. 0.4 A

27.

Why is a very high voltage being used when transporting electricity over long distances?

a. Then the current is small

b. the loss of energy is small

c. this is just the way it is being done

28.

How often does one need to use one's call sign during a QSO ?

a. at the beginning and at the end of a QSO

b. every time when the microphone (or key) is passed on to the other party

c. every five minutes

d. this is just for dumbo's

29.

a. 0 V.

b. 2 V.

c. 4 V.

d. 8 V.

30.

a. 0.5 A

b. 1 A

c. 1.5 A

d. 2 A

31.

The internal resistance of this power source is:

a. very high
b. dependant of the current
c. low
d. zero

32.

The characters R F are spelled with the NATO alphabet as:

a. Radio - Fox ; b. Romeo - Fox ; c. Radio - Foxtrot ; d. Romeo - Foxtrot

33.

A radio-electrical transmission installation consists of:

a. A transmitter with its antenna ; b. the transmitter ; c. the transceiver ; d. the transceiver with its antenna.

34.
The unit for the magnetic field is:

a. V/m b. A/m c. V.m. d. Am

35.

The unit for the electro-magnetic field is:

a. V/m b. Watt/m c. Watt/m² d. A.V/m

36.

U_AB = ?

a. 8 Volt
b. 5,6 Volt
c. 4 Volt
d. 2 Volt

37.

How much power is used in this diagram with an open and a closed switch?

a. 4 and 2 watt
b. 4 and 4 watt
c. 4 and 16 watt
d. 4 and 8 watt

38.

E = 20 Volt; I = 1 A. U_Ri = 2 Volt; U_Ru = 18 Volt. What is the value of R_i ?
a. 0.5 Ω
b. 1 Ω
c. 2 Ω
d. 4 Ω

39.

The speed of light is:

a. 3 km/h b. 300,000 km/h c. 300,000 km/s d. 300,000,000 km/s

40.

The frequency depends on:

a. the wave length b. the delay factor c. light d. the conductor

41.

a. 0 Volt

b. 7 Volt

c. 5 Volt

d. 4 Volt

42.
Four AAA penlight batteries are put in a portable radio. One of the AAA batteries is erroneously inserted in reverse.
How much voltage does the radio get?

a. 6 Volt b. 4.5 Volt c. 3 Volt d. - 1.5 Volt

43.
a. 50 Hz

b. 100 Hz

c. 500 Hz

d. 1 kHz

44.
U_AB = ?

a. 15 Volt
b. 10 Volt
c. 6 Volt
d. 16 Volt

45.
The effective voltage of a sinus AC with an amplitude of 20 Volts is (approx.) ?
a. 6.4 Volt b. 7 Volt c. 12.8 Volt d. 14 Volt

46.
Is a ham operator allowed to work with other CB operators on 27 MHz ?
a. as compliant with the regulations: only with other ham operators.
b. only if his transmission power stays within the power limits
c. of course
d. only if approved equipment (CE) for CB usage is being used.

47. A 100 Watt AM transmitter is approximately equal to:

a. 100 Watt FM transmitter with 5 kHz frequency sweep
b. 50 Watt SSB transmitter
c. 25 Watt SSB transmitter
d. 400 Watt SSB transmitter

48. An FM transmitter has a 5 kHz sweep and the highest LF-frequency is 2.5 kHz. The modulation-index is:

a. 15 b. 12.5 c. 2 d. 0.5

49. The transmitter of question number 48 has a bandwidth of:

a. 15 kHz b. 7.5 kHz c. 5 kHz d. 2.5 kHz

50. Which modultion-type contains 100% information in the signal?

a. FSK b. AM c. CW d. PM

51.
Here a signal gets digitized. What is the right order?

a. 1. sampler   2. D/A converter   3. reconstruction filter
b. 1. anti aliassing filter   2. sampler   3. A/D converter
c. 1. anti aliassing filter   2. sampler   4. D/A converter
d. 1. sampler   2. anti aliassing filter   3. A/D converter

52.
What is the characteristic of a binairy system ?

a. it has a number sequence from 1 to 10
b. it has 6 numbers and 6 characters
c. it is a logarithmic system
d. it represents two switching levels

53.
QAM can be described as:

a. an analogue method b. switching using BPSK c. switching using FSK d. switching using PSK on different levels

54.
A five bits PSK signal has:

a. 128 positions b. 64 positions c. 32 positions d. 16 positions

55.
The speed of a digital signal is given as:

a. kHz b. bits/second c. byte/second d. bit * second

56.
U1 = 5V
U2 = 5V

R1 = 4Ω
R2 = 6Ω

U_AB = ?

a. 0 Volt b. 2 Volt c. 4 Volt d. 18 Volt

57.
What voltage does the Volt meter show?

a. 10 Volt

b. 8 Volt

c. 2 Volt

d. 0 Volt

58.
What is the value of the short circuit current?

a. 0 A.
b. 1 A.
c. 3.33 A.
d. 7.4 A.

59.
With AMTOR ARQ:

a. there is no error correction b. each character is sent twice c. the other 'party' gives an acknowledgement d. is only used with FSK

60.
When a 100 Watt carrier is 100% AM modulated:

a. is the PEP 400 Watts b. is the PEP 100 Watt c. is the PEP 50 Watt d. is the PEP 25 Watt

61.
How do we call the broadband noise that has an equal amplitude across the whole spectrum?

a. quantisising noise b. brown noise c. cosmic noise d. white noise.

62.
Why do we need to sample an analogue signal before we can send it digitally?

a. to obtain the different voltage levels required by the A/D converter b. to allow the phase jumps in the HF signal c. to avoid quantisising noise d. with no sampling one gets aliassing.

63.
How much power is dissipated in this configuration ?

a. 6 Watt b. 8 Watt c. 10 Watt d. 14 Watt

64.
Which statement is correct?
a. the current and voltage are in phase
b. the voltage is leading the current
c. the current is leading the voltage
d. the current lags the voltage

65.
Which formula is correct?

a. C = 1/2∏f.X_c b. C = 2∏f_c c. C = 2∏F/X_c d. C = X_c/2∏f

66.
U_AB = ?

a. 0 V. b. 2 V. c. 4 V. d. 6 V.

67.
C₁ = C₂ = 10µF. What is the replacement value C_rv ?

a. 20µF b. 10µF c. 5 µF d. 2.5 µF

68.
C_rv = ? (RV stands for replacement value)

a. 2µF
b. 0.8 µF
c. 8µF
d. 5µF

78.
How large is the impedance of a coil using VDC ?

a) equal to R b) √X_L² + R² c) 1/√X_L² + R²d) very high

79.
The formula for impedance X_L is:

a) X_L = 1/2∏f.L b) X_L = 2∏f/L c) X_L = 2∏f.L
d) X_L = ω/2∏f.L

80.
Coils in HF circuits are shielded using:

a) aluminium b) wood c) tinplate d) magnetic tinplate

81.
The unit for the magnetic field H is:

a) Henry b) A/m c) Am d) V/m

91.

With a secundaire assignment of an amateurband the amateurs need to:

a. give priority to all other users
b. give priority to all other secundary users
c. give priority to primary users
d. doesn't matter what

a. Q = c.u
b. c = u/Q
c. c= Q/u²
d. c = Q/u

109. The collector dissipation of assignment 108 is:

a) 0 W b) 3 mW c) 10 mW d) 13 mW

111. The current in assignment 110. is 1 A. How much power is being dissipated?

a) 0 W b) 4 W c) 5000 W d) 5004 W.

117.
Which statement is correct?

a) at a capacitor the current leads the voltage
b) at a capacitor the voltage leads the current
c) at a coil the current leads the voltage
d) none of the above is correct.

119.
A lead-acid battery of 12 Volt contains:

a) 1 cell b) 6 cells c) 10 cells d) 12 cells

122.

A practical value for a Pulse Width Modulator in a switching power supply is:

a) 10 Hz b) 50 Hz c) 1 kHz d) 15 kHz

125.
A radio amateur is asking a fellow radio amateur to deliver a message to his neighbour. This is:

a) allowed b) allowed unless it is a commercial message c) not allowed

126.

Home made equipment (receiver) is:

a) allowed b) not allowed c) allowed, provided it complies to certain specifications d) allowed, provided it is approved by the appropriate government agency

132. A PLL circuit uses what type of oscillator?

a) Collpits b) Hartley c) crystal d) VCO

Note: Voltage reduced i.e. less positive (+); Voltage increases i.e. more positive (+).

145.
A device is using 2700 joules during 15 minutes. What is the power consumption of that device?

a) 3 W b) 180 W c) 675 W d) 2700 W

146.
A FM transmitter has a 5 kHz sweep and is modulated with a 2.5 kHz tone.
What is the modulation index?

a) 0.5 b) 2 c) 12.5 d) 15

147.
In order to gain one (1) S-point, the transmit power should:

a) not change b) increase four (4) times c) increase two (2) times
d) increase ten (10) times

148.
On a well adjusted and tuned FM receiver an FM transmission sounds crumbled and heavily distorted. What is the cause?

a) The power amplifier (PA) of the transmitter is set in class C.
b) The squelch of the receiver is set to tight
c) the transmitter has a sweep that is too large
d) the transmitter has a sweep that is too small

149.
The nearby selectivity of a receiver is determined by:

a) the tuning at the input b) the balance mixer
c) a high quality crystal filter in the MF circuit d) a DSP audio unit.

150.
FM is being modulated with:

a) a diode detector b) FM-discriminator c) a product-detector
d) a flank-detector

151.
A ham transceiver working in the 70 MHz band is causing QRM on the DAB⁺ reception in band III (176-230 MHz). This QRM can be prevented by:

a) putting a low pass filter in the modulator
b) putting a low pass filter in the antenna of the transmitter
c) putting a high pass filter behind the transmitter
d) to only work FM

152.
A receiver is connected with its antenna using a long coax-cable. To avoid signal-loss it is best to:

a) install a pre-amplifier near the antenna
b) install a pre-amplifier near the receiver
c) apply a large MF amplification
d) apply a large LF amplification

153.
A noise having an equal amplitude over a large bandwidth is called:

a) thermic noise b) cosmic noise c) white noise d) brown noise

Here I end my contribution to get familiar with the F license stuff, knowing there are many more items I could (or should) have addressed.