CRAC Class C (2025) — Questions 481–490

0 / 10

U0828. The encoding amateur radio operators use to mark their own station location with the Maidenhead grid locator may have 4 or 6 characters. The two differ in positioning accuracy: the difference is:

业余无线电爱好者使用梅登海德网格定位系统标示己方电台位 置所用的编码可以具有4个或6个字符。二者的定位精度不同, 区别为:

Exam tips · 考试提示

A 4-character Maidenhead grid (field+square) spans 2° longitude × 1° latitude; adding the 2-letter subsquare (6 characters) narrows it to 5′ longitude × 2.5′ latitude (A). The other options mischaracterize the distinction (administrative, call-sign based, or mode-based).

U0829. To facilitate time calculation, the Earth is divided into several time zones; the method of dividing each theoretical time zone is:

为了便于计算时间,将地球划分为若干个时区,各理论时区的 划分方法是:

Exam tips · 考试提示

The theoretical time-zone system divides the Earth into 24 zones of 15° longitude each (360°/24 = 15°), with the prime meridian (0° longitude) through the center of zone 0 (A). The 12-zone versions (B, D) are wrong, and C misstates the boundaries as 15° multiples rather than centered on the prime meridian.

U0830. To facilitate time calculation, the Earth is divided into time zones; the naming rule of each theoretical time zone is:

为了便于计算时间,将地球划分为若干个时区,各理论时区的 命名规则是:

Exam tips · 考试提示

Zone 0 is centered on the prime meridian; moving east gives East 1–East 12 and moving west gives West 1–West 12 (A). There is no zone 13–24 in the standard scheme (B, C, D are wrong).

U0831. To facilitate time calculation, the Earth is divided into time zones; Beijing's situation is:

为了便于计算时间,将地球划分为若干个时区,北京的情况 是:

Exam tips · 考试提示

Beijing is in East 8 (UTC+8), so its local time is 8 hours ahead of zone 0 (UTC/GMT) time (A). Being east of the prime meridian means earlier (ahead) local time, not later.

U0832. To facilitate time calculation, the Earth is divided into time zones; the theoretical division is 15 degrees per zone. The time zones that Beijing, Xi'an and Urumqi actually belong to are:

为了便于计算时间,将地球划分为若干个时区,其理论分区为 每区宽经度15度。北京、西安和乌鲁木齐实际所属的时区应 为:

Exam tips · 考试提示

Although geographically Urumqi's longitude would suggest East 6, China uses a single legal time zone (Beijing Time, UTC+8) nationwide, so Beijing, Xi'an, and Urumqi all officially belong to East 8 (A). The longitude-deduced answers (B, C, D) ignore the legal uniform time zone.

U0833. Given Beijing time, the corresponding UTC time should be:

已知北京时间,相应的UTC时间应为:

Exam tips · 考试提示

Beijing time = UTC+8, so UTC = Beijing time − 8 hours. When that subtraction yields a negative hour, you add 24 and step back one day (A). Adding 8 (C, D) is the reverse (Beijing-from- UTC) direction and is wrong here.

U0834. Given UTC time, the corresponding Beijing time should be:

已知UTC时间,相应的北京时间应为:

Exam tips · 考试提示

Beijing time = UTC + 8. So take UTC hours, add 8; if the result exceeds 24, subtract 24 and advance the date by one day (A). Options B/C/D incorrectly operate on "Beijing time" or move the date backward.

U0835. Given an amateur station is in a West-N time zone (N an integer from 0 to 12), its local time should be ___ than Beijing time:

已知某业余电台处于西N时区(N为0-12间的整数),该台的 当地时间应比北京时间:

Exam tips · 考试提示

Beijing is UTC+8; a West-N zone is UTC−N. The difference (Beijing − local) = 8 − (−N) = 8+N hours, meaning the local time is behind (later, 晚) Beijing by 8+N hours (A). East is ahead, west is behind.

U0836. Given an amateur station is in an East-N time zone (N an integer from 0 to 12), its local time should be ___ than Beijing time:

已知某业余电台处于东N时区(N为0-12间的整数),该台的 当地时间应比北京时间:

Exam tips · 考试提示

Beijing is UTC+8; an East-N zone is UTC+N. The difference is (Beijing − local) = 8 − N hours. For the typical case N<8 the local time is behind Beijing ("晚", later) by 8−N hours, which is the form given in the official answer (A). The formula expresses the standard comparison with Beijing as reference.

U0837. If while participating in an amateur radio CW contest you copy "B4" or "WKD", it means:

如果在参加业余无线电CW竞赛时抄下"B4"或"WKD"则说明:

Exam tips · 考试提示

In CW contesting, "B4" (before) and "WKD" (worked) are sent by a station to tell you it has already worked you — a duplicate. The correct response is to check your own log rather than re- log the contact (A). Re-calling (B), deleting records (C), or treating it as a friendly greeting (D) are wrong.