Answers belonging to the VERON F registration training class questions published on my Ham Radio page

1. D. ± 28 V. N1:N2 = 1000:100 = 10:1 = 200:20 = 20 Veff. C is a large capacitor that will charge to the full without discharge. So Vmax of 20 Veff is 20* √2 = ± 28 V.

2. C. f=1/t

3. A. 0 Volt. Total U = 2+4 = 6 Volt. I = U/Rtot = 6/12 = 0,5 A. VR1=2 Volt; VR2=4 Volt. Going round the circuit using the rules of Kirchhoff gives you VAB = 0 Volt.

4. C. Low voltage amplification. Re doesn't have a capacitor and thus causes feedback on VRb in antiphase.

5. C. Oscillator. See the feedback between Collector and Basis with an L/C circuit having a certain resonance.

6. C. Note: A is an PNP transistor; the others are NPN transistors. Example C has a positive voltage on the basis (minimum required is + 0.7 Volt, with silicium or + 0.2 with germanium)

7. C. P=I*U.  U=I*R.  P=I2*R.  2=I2*50.  I2=2/50.  I=√2/50 = √1/25 = 1/5 = 0,2 = 200 mA.

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8. A. 0 Amp

9. B.

10. D. Ia*Rk . VRk makes the cathode positive in relation to the screen grid, resulting in a negative voltage on the screen grid in relation to the cathode.

11. A. 34 kHz (minimum of 2 * analogue frequency)

12. B. Quantization noise is caused by square waves.

13. A. Binairy code

14. C. BPSK (binairy phase shift keying)

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

16. b. 2 A.

17. c. 2 Ω

18. c. watt/second (≠ wattsecond !)

19. b. 0.04 Watt

20. b. 2 x

21. d. 16 Watt

22. b. Uk = 9 Volt

23. b. 10 Amp.

24. d. 1 Amp

25. c. Coulomb

26. c. 4 Amp.

27. b. the loss of energy is small

28. c. every five minutes.

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29. b. 2 Volt

30. a. 0.5 Amp

31. d. zero

32. d. Romeo Foxtrot

33. a. a transmitter with its antenna.

34. b. A/m

35. c. Watt/m2

36. c. UAB = 4 Volt

37. d. 4 and 8 Watt

38. c. 2 Ω

39. c. 300,000 km/sec

40. a. wavelength

41. c. 5 Volt

42. d. 3 Volt !

43. a. 50 Hz.

44. b. 10 Volt

45. d. 14 Volt (20/√2 = 0.7*20)

46. d.

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47. c. 25 Watt SSB

48. c. 2

49. a. 15 kHz (B = 2*fLf(max) + 2*ΔF) ;  fLf(max) = 2.5 kHz; ΔF = sweep = 5 kHz

50. c. CW (Morse)

51. b. 1. anti-aliassing filter  2. sampler   3. A/D converter

52. d. it represents two switching levels

53. d.

54. c.

55. b.  bits/second

56. a. 0 Volt

57. d. 0 Volt

58. c.

59. c.

60. a. 400 Watt

61. d. white noise

62. a.

63. a. 6 Watts (only in the resistor)

64. c.

65. a.

66. b.

67. c. 5 µF

68. a. 2 µF

69. d. very high (resonance)

70. b. 4Ω

71. b. C1

72. b. 10

73. b. 6 V

74. a. 10 V.

75. c. 0.2 A

76. c.

77. c. 5 mH

78. a. equal to R

79. c.

80. a. aluminium

81. b. A/m

82. c.

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83. a. 0 A.

84. a. 25 V.

85. d. twin lead

86. c. direct current resistors (load)

87. d. 12 Watt

88. a. 4 x

89. b. 4 x

90. c. 200 Ω

91. c.

92. a. en d.

93. c. capacitive.

94. a. Q=XL/Rs = 50

95. a. 6 Watt (the powerloss only occurs across the resistor)

96. c. 20 Watt

97. c. 1.4 Volt (2 x 0.7)

98. d. indefinite (in theory)

99. d. 10 Volt (7,1 * √2)

100. c. NPN transistor

101. c. 9.3 Volt

102. c. 2 Ω

103. c. 10.1 mA

104. a. to prevent the valve getting cut off

105. b. 0.5 V

106. b. 1.01 mA

107. a.

108. b.  3 V

109. b. 3 mW

110. d. 4 Ω

111. b. 4 W.

112. c. 1 V

113. c. C2 is defective and causes a short circuit.

114. c. 2 A.

115. c. high voltage. A low voltage unit would have a much larger capacitor to get rid of the AC ripple on the DC voltage. A low voltage unit would also have an additional stabilisation circuitry.

116. d. 30 sec. the time constant t equals: t=R*C. It takes 3 times the time constant to discharge a capacitor up to about 95%. Theoretically a capacitor never gets fully discharged.

117. a. At a capacitor in a AC circuit the current leads the voltage. In a vectordiagram the current vector is 90o ahead of the voltage vector.

118. c. low pass filter in e.g. an audio amplifier.

119. b. 6 cells; each cell has ±2 V.

120. b

121. c. Pulse Width Modulator (PWM)

122. d. 15 kHz

123. b. Au = R2/R1

124. a. phase shifter

125. c.

126. c.

127. d.

128. b.

129. d.

130. b.

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131. c.

132. d.

133. a. (when + increases than the capacity becomes less, vica versa)

134. c.

135. b.

136. b.

137. d.

138. a. 0 Volt

139. c.

140. c.

141. c.

142. b.

143. d.  28 Volt

144. b. 25 kHz

145. a. 3 watt

146. b. 2

147. b. 4 times. equals 6 dB; equals 1 S-point

148. c.

149. c.

150. b.

151. b.

152. a.

153. c.

154. b.