CRAC Class C (2025) — Questions 961–970
U1046. The monolithic capacitor (独石电容) that we often use is a:
我们经常使用的独石电容是一种：
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独石电容 (monolithic/"mono" capacitor) is a 多层陶瓷电容 (multilayer ceramic capacitor, MLCC) — many ceramic layers fired into one block. It is not mica, wound polyester, or a single-layer high-frequency ceramic cap.
U1047. Among the components used in assembling amateur transceivers, those typically marked with a rated voltage- withstanding (voltage rating) are: (Choose all that apply.)
在组装业余收发信机所用的元器件中，标有额定耐压的通常 是：
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electrolytic capacitors (电解电容) and tantalum capacitors (钽电 容) carry a rated voltage (e.g., 16 V, 35 V) that must not be exceeded, and a 熔丝 (fuse) is also marked with a rated voltage in addition to its rated current. An inductor/coil (电感线圈) is not normally marked with a voltage rating, so D is excluded.
U1048. When building homemade circuit projects, hobbyists often replace electrolytic capacitors of about 1–100 µF with surface- mount ceramic capacitors of the same capacitance. The advantages of the latter are: (Choose all that apply.)
在自制电路作品时，爱好者们经常将容量约为1-100μF的电解 电容替换为同等容量的贴片陶瓷电容。后者的优点是：
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Compared with electrolytics, an SMD ceramic of equal capacitance is smaller (A), has far better high-frequency behavior with low ESR/ESL (B), is non-polarized so it cannot be reverse-connected (C), and is far more reliable with no electrolyte to dry out, giving a lower failure rate (D). All four are genuine advantages of ceramic replacement.
U1049. In a circuit diagram, if the capacitance value of an electrolytic capacitor is not marked with a unit, the default unit is:
电路图中，若电解电容器的容量未标注单位，则默认为：
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Per the schematic convention for 电解电容器 (electrolytic capacitors), an unmarked capacitance unit is taken to belong to the farad family (法拉) — electrolytic values are normally written as a plain number meaning microfarads in practice, but the examination convention classifies the implied base unit as the farad. The other units are used for other conventions.
U1050. In a circuit diagram, if the capacitance of a non-electrolytic capacitor is marked with an integer or decimal greater than 1, the default unit is:
电路图中，若用大于1的整数或小数标注非电解电容器的容量， 则单位缺省为：
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For a 非电解电容器 (non-electrolytic capacitor), a value written as a number greater than 1 with no unit defaults to picofarads (皮法拉, pF) — e.g., "100" means 100 pF. This contrasts with electrolytic-capacitor convention.
U1051. If you see a non-electrolytic capacitor's value marked with a 3-digit code on a circuit diagram or the actual component, it should be read as:
如果在电路图中或实际元件上看到用3位数字标明的非电解电容 器的容量时应读为：
Exam tips · 考试提示
The standard 3-digit capacitor code uses the first two digits as the significant value and the third as the multiplier (number of zeros), with the result in picofarads (pF). So "104" = 10 followed by 4 zeros = 100,000 pF = 100 nF. Option B/C/D describe wrong decoding rules.
U1052. If you see a resistance value marked with a 3-digit code on a circuit diagram or the actual component, it should be read as:
如果在电路图中或实际元件上看到用3位数字标明的阻值时应读 为：
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The 3-digit resistor code works exactly like the capacitor code: first two digits are significant, the third is the multiplier (zeros), result in ohms. "472" = 47 with 2 zeros = 4700 Ω = 4.7 kΩ. The other options give wrong math or units.
U1053. If you see a resistance marked with 2–3 digits and a letter (e.g., 8R2, 2K7, 1M5) on a diagram or component, it should be read as:
如果在电路图中或实际元件上看到用2至3位数字和一个字母 （例如8R2、2K7、1M5）标明的阻值时应读为：
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In the letter-coded resistor marking, the letter is the decimal point: 8R2 = 8.2 Ω, 2K7 = 2.7 kΩ, 1M5 = 1.5 MΩ. R/K/M set the unit as ohms/kilohms/megohms. Options B/C/D misread the letter as a multiplier or a tolerance marker.
U1054. In a circuit diagram, if the capacitance of a non-electrolytic capacitor is marked with a decimal less than 1, the default unit is:
电路图中，若用小于1的小数标注非电解电容器的容量，则单位 缺省为
Exam tips · 考试提示
For a 非电解电容器 (non-electrolytic capacitor) written as a decimal below 1 with no unit, the default is microfarads (微法 拉, µF) — e.g., "0.1" means 0.1 µF. This is the third of the three schematic capacitance conventions (with >1 → pF, <1 → µF).
U1055. In amateur transceivers, the component used to block DC or to provide a bypass for AC signals is:
在业余收发信机中用来阻断直流或者为交流信号提供旁路的元 件是：
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A 电容 (capacitor) passes AC while blocking DC (high reactance at DC, low at AC), making it the element used both to block DC and to bypass (short) AC signals to ground. Resistors dissipate, inductors block AC, diodes rectify — none fits both roles.