Q21
5 marksLong AnswerSection D

What is a solenoid? Draw the pattern of magnetic field lines of (i) a current carrying solenoid and (ii) a bar magnet. List two distinguishing features between the two fields.

Figure for question 21
Magnetic Effects of Electric Current
Magnetic Field Lines
Official Answer

A solenoid is a coil of wire through which an electric current flows. The pattern of magnetic field lines of a current-carrying solenoid is similar to that of a bar magnet, with the magnetic field lines emerging from the north pole and entering the south pole. However, there are two distinguishing features between the two fields: (i) The magnetic field lines of a solenoid are more uniform and symmetrical than those of a bar magnet. (ii) The magnetic field of a solenoid can be controlled by changing the current flowing through the coil, whereas the magnetic field of a bar magnet is fixed.

solenoidmagnetic field linesbar magnetuniformsymmetricalcontrolled

Marking Scheme

  • 1Magnetic field lines of a current-carrying solenoid are similar to those of a bar magnet.
  • 2Magnetic field lines of a solenoid are more uniform and symmetrical than those of a bar magnet.
  • 3Magnetic field of a solenoid can be controlled by changing the current flowing through the coil, whereas the magnetic field of a bar magnet is fixed.

Hint

Think about the shape of the magnetic field lines around a current-carrying solenoid and a bar magnet. How do they differ? What are the reasons for these differences?

Quick Oral Answer

A solenoid is a coil of wire through which an electric current flows. The pattern of magnetic field lines of a current-carrying solenoid is similar to that of a bar magnet, with the magnetic field lines emerging from the north pole and entering the south pole. However, there are two distinguishing features between the two fields: (i) The magnetic field lines of a solenoid are more uniform and symmetrical than those of a bar magnet. (ii) The magnetic field of a solenoid can be controlled by changing the current flowing through the coil, whereas the magnetic field of a bar magnet is fixed.

Analysis & Explanation

The question requires the student to understand the concept of magnetic field lines and how they are affected by the presence of a current-carrying solenoid or a bar magnet. The student must be able to identify the similarities and differences between the two fields and explain the reasons behind these differences.

Common Mistakes

  1. 1Confusing the magnetic field lines of a solenoid with those of a bar magnet.
  2. 2Failing to recognize the differences between the two fields.
  3. 3Not understanding how the magnetic field of a solenoid can be controlled.

Interesting Facts

The magnetic field of a solenoid can be used to create a magnetic resonance imaging (MRI) machine.

The magnetic field of a bar magnet is used in many applications, including motors, generators, and magnetic storage devices.

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2019?

This question carries 5 marks in the CBSE Class 10 Science 2019 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 Lines" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2019 paper?

This is a Long Answer question from Section D in the CBSE Class 10 Science 2019 paper.