Two coils of insulated copper wire are wound over a non-conducting cylinder as shown. Coil 1 has comparative large number of turns. State your observations, when (i) Key K is closed. (ii) Key K is opened. Give reason for each of your observations.
Two coils of insulated copper wire are wound over a non-conducting cylinder as shown. Coil 1 has comparative large number of turns. State your observations, when (i) Key K is closed. (ii) Key K is opened. Give reason for each of your observations.
Official answer
When key K is closed, a current flows through coil 1 and coil 2. Since coil 1 has a larger number of turns, the magnetic field produced by it is stronger. The magnetic field lines emerge from the north pole of coil 1 and enter the south pole of coil 2. When key K is opened, the current through both coils stops, and the magnetic field disappears.
Marking scheme
- 1.Magnetic field due to a current through a straight conductor
- 2.Right-hand thumb rule
Hint
Use the right-hand thumb rule to determine the direction of the magnetic field.
Quick oral answer
The magnetic field produced by a current-carrying conductor depends on the number of turns of the conductor. In this case, coil 1 has a larger number of turns, so it produces a stronger magnetic field. When the key is closed, the current flows through both coils, and the magnetic field is present. When the key is opened, the current stops, and the magnetic field disappears.
Common mistakes
- 1.assuming that the magnetic field is the same for both coils
- 2.not considering the direction of the magnetic field
Analysis and explanation
The magnetic field produced by a current-carrying conductor depends on the number of turns of the conductor. In this case, coil 1 has a larger number of turns, so it produces a stronger magnetic field. When the key is closed, the current flows through both coils, and the magnetic field is present. When the key is opened, the current stops, and the magnetic field disappears.
Interesting facts
The magnetic field produced by a current-carrying conductor can be used to create an electromagnet.
The strength of the magnetic field depends on the number of turns of the conductor.
Question details
Q23 of 45 questions
- Board
- CBSE
- Class
- Class 10
- Subject
- Science
- Year
- 2020
- Section
- Section B
- Marks
- 3
- Type
- Short Answer
- Chapter
- Magnetic Effects of Electric Current
- Topic
- Magnetic Field
- Bloom's level
- Comprehension
- Syllabus topic
- Magnetic Field due to a Current through a Straight Conductor
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Frequently asked questions
How many marks does this question carry in CBSE Class 10 Science 2020?
This question carries 3 marks 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 "Magnetic Field" from CBSE Class 10 Science.
What type of question is this in the CBSE Class 10 Science 2020 paper?
This is a Short Answer question from Section B in the CBSE Class 10 Science 2020 paper.