(a) What are geothermal energy hot-spots?
(a) What are geothermal energy hot-spots?
Official answer
An important advantage of using Alternating Current (AC) over Direct Current (DC) is that electric power can be transmitted over long distances without much loss of energy.
Marking scheme
- 1.Stating that AC can be transmitted over long distances: 0.5 mark
- 2.Stating that it occurs with minimal loss of energy/power: 0.5 mark
Hint
Think about how electricity is transported from power plants to distant cities with minimal power loss.
Quick oral answer
The main advantage of AC over DC is that AC can be transmitted over very long distances with minimal energy loss because its voltage can be easily stepped up and down using transformers.
Common mistakes
- 1.Stating that AC is safer than DC (AC is actually more dangerous at similar voltages).
- 2.Confusing the direction of current flow with transmission efficiency.
Analysis and explanation
Alternating current (AC) can be easily stepped up to high voltages using transformers for transmission. High-voltage transmission significantly reduces the current () flowing through the transmission lines, which exponentially decreases the power loss due to Joule heating (). Once the power reaches its destination, it can be stepped down to safe, usable voltages for domestic consumption. Direct current (DC) cannot be stepped up or down easily with high efficiency, resulting in substantial energy losses over long distances.
Interesting facts
The 'War of the Currents' in the late 1880s was a series of events surrounding the introduction of competing electric power transmission systems. Thomas Edison promoted Direct Current (DC), while Nikola Tesla and George Westinghouse championed Alternating Current (AC). AC ultimately won because of its superior long-distance transmission efficiency.
Question details
Q3 of 45 questions
- Board
- CBSE
- Class
- Class 10
- Subject
- Science
- Year
- 2020
- Section
- Section A
- Marks
- 1
- Chapter
- Magnetic Effects of Electric Current
- Topic
- Alternating Current (AC) and Direct Current (DC)
- Bloom's level
- Remembering
- Syllabus topic
- Advantage of AC over DC
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Frequently asked questions
How many marks does this question carry in CBSE Class 10 Science 2020?
This question carries 1 mark in the CBSE Class 10 Science 2020 examination.
Which chapter does this question come from in Science?
This question is from the chapter "Magnetic Effects of Electric Current" in the CBSE Class 10 Science syllabus.
What topic does this question cover in Science?
This question covers the topic "Alternating Current (AC) and Direct Current (DC)" from CBSE Class 10 Science.
What type of question is this in the CBSE Class 10 Science 2020 paper?
This question appears in Section A in the CBSE Class 10 Science 2020 paper.