NCERT Class 10 Science — Chapter 4: Magnetic Effects of Electric Current

With reference to magnetic field lines, consider the following statements: 1. Outside a magnet, they are taken to originate from the north pole and terminate at the south pole. 2. Inside a magnet, they run from the south pole to the north pole. 3. The closeness of lines is independent of the relative strength of the field. 4. Two magnetic field lines can intersect at a point. Which of the statements given above is/are correct?

Assertion (A): Magnetic field is a vector quantity. Reason (R): Magnetic field lines are closer together where the magnetic field is strong.

Assertion (A): The magnetic field is stronger near the poles of a magnet. Reason (R): The magnetic field lines are widely spaced near the poles.

Which of the following changes will increase the displacement of a current-carrying rod in a uniform magnetic field? 1. Increasing the current reduces the displacement of the rod. 2. Using a stronger magnet. 3. Increasing the effective length within the field has no effect on displacement. Which of the statements given above is/are correct?

Which medical imaging technique relies on strong magnetic fields and radio waves?