CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
When it is 12:00 noon at Greenwich, the local solar time at 30° W is:
A. 10:00 am
B. 11:00 am
C. 1:00 pm
D. 2:00 pm
Correct Answer: A
30° west equals 2 hours behind Greenwich; 12:00 noon − 2 hours = 10:00 am.
CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
When it is 12:00 noon at Greenwich, the local solar time at 15° E is:
A. 11:00 am
B. 12:30 pm
C. 1:00 pm
D. 2:00 pm
Correct Answer: C
15° east is one hour ahead of Greenwich, so the time is 1:00 pm.
CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
If two places differ by 30° of longitude, their local solar times differ by:
A. 30 minutes
B. 1 hour
C. 2 hours
D. 4 hours
Correct Answer: C
30° ÷ 15° per hour = 2 hours.
CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
The main geographical basis of world time zones is:
A. Latitude
B. Longitude
C. Elevation
D. Ocean currents
Correct Answer: B
Time-zone offsets are fundamentally related to longitude and Earth's rotation.
CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
Standard time was introduced mainly to:
A. Increase the number of local times
B. Provide a common time for a region
C. Eliminate longitude
D. Change the length of the day
Correct Answer: B
Standard time allows a large region to use one common clock time instead of many local solar times.
CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
Local solar time is primarily determined by:
A. Latitude
B. Longitude
C. Altitude
D. Rainfall
Correct Answer: B
Local solar time changes with longitude because different meridians face the Sun at different times.
CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
A time zone is best described as:
A. A region using the same standard time
B. A line of latitude
C. A climatic region
D. A political boundary only
Correct Answer: A
A time zone is a region in which the same standard time is observed.
CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
Ideally, the width of a one-hour time zone is:
A. 7.5° longitude
B. 10° longitude
C. 15° longitude
D. 30° longitude
Correct Answer: C
Each ideal one-hour zone spans 15° of longitude.
CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
The ideal number of one-hour time zones around the Earth is:
A. 12
B. 18
C. 24
D. 36
Correct Answer: C
A 360° globe divided into 15°-wide ideal zones gives 24 time zones.
CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
Places located west of Greenwich are generally:
A. Ahead of Greenwich time
B. Behind Greenwich time
C. Always 12 hours ahead
D. Always one day ahead
Correct Answer: B
Local solar time is earlier at longitudes west of Greenwich.
CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
Places located east of Greenwich are generally:
A. Behind Greenwich time
B. Ahead of Greenwich time
C. Always on the same time
D. One day behind
Correct Answer: B
Because Earth rotates west to east, local solar time becomes later toward the east.
CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
The historic Prime Meridian passes through:
A. Paris
B. Rome
C. Greenwich
D. New York
Correct Answer: C
The historic Prime Meridian was established at the Royal Observatory, Greenwich.
CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
The Prime Meridian is assigned which longitude?
A. 90° E
B. 0°
C. 90° W
D. 180°
Correct Answer: B
The Prime Meridian is the reference meridian at 0° longitude.
CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
A difference of 1 minute of longitude (1′) corresponds to approximately:
A. 2 seconds of time
B. 4 seconds of time
C. 6 seconds of time
D. 10 seconds of time
Correct Answer: B
1° = 4 minutes of time; therefore 1′ of longitude = 4 seconds of time.
CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
A difference of 1° of longitude corresponds to approximately:
A. 2 minutes of time
B. 4 minutes of time
C. 6 minutes of time
D. 8 minutes of time
Correct Answer: B
Since 15° = 60 minutes of time, 1° = 4 minutes of time.
CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
The Earth rotates through how many degrees of longitude in one hour?
A. 10°
B. 12°
C. 15°
D. 20°
Correct Answer: C
360° ÷ 24 hours = 15° of longitude per hour.
CSS - PMS - CCE - PCS - Geography
Time Zones and International Date Line
The Earth completes approximately one rotation in:
A. 12 hours
B. 24 hours
C. 36 hours
D. 48 hours
Correct Answer: B
Earth's rotation is conventionally treated as 360° in about 24 hours for time-zone calculations.