Chapter 5: Magnetism and Matter Assertion Reason
These questions of two statements each, printed as Assertion and Reason. While answering these Questions you are required to choose any one of the following four responses.
(A) If both Assertion & Reason are true & the Reason is a correct explanation of the Assertion.
(B) If both Assertion and Reason are true but Reason is not a correct explanation of the Assertion.
(C) If Assertion is true but the Reason is false.
(D) If Assertion & Reason both are false.
Assertion-Reason Questions
- Assertion (A): A freely suspended magnet always aligns itself in the north-south direction.
Reason (R): The earth behaves as a huge bar magnet with its magnetic north pole near the geographic south pole and vice versa.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): Magnetic field lines never intersect each other.
Reason (R): At the point of intersection, there would be two directions of the magnetic field, which is not possible.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The magnetic declination at a place varies with time.
Reason (R): The position of the magnetic north and south poles of the earth changes with time.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): A diamagnetic material is repelled by a magnet.
Reason (R): Diamagnetic materials have no net magnetic moment in the absence of an external magnetic field.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The magnetic susceptibility of a paramagnetic material is positive.
Reason (R): Paramagnetic materials are weakly attracted by a magnet.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): A ferromagnetic material becomes a permanent magnet when placed in a strong magnetic field.
Reason (R): Ferromagnetic materials have large positive magnetic susceptibility.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The magnetization of a material depends on temperature.
Reason (R): The alignment of magnetic dipoles in a material changes with temperature.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): Soft iron is used to make electromagnets.
Reason (R): Soft iron has high retentivity and coercivity.
Answer: A is true but R is false. - Assertion (A): The earth’s magnetic field is uniform over its surface.
Reason (R): The earth’s magnetic field is generated by the motion of molten iron in its outer core.
Answer: A is false but R is true. - Assertion (A): Magnetic monopoles do not exist.
Reason (R): Magnetic field lines are continuous and form closed loops.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The magnetic permeability of a material is the measure of its ability to support the formation of a magnetic field.
Reason (R): The permeability of a material is the ratio of the magnetic flux density to the magnetic field strength in the material.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The Curie temperature is the temperature above which a ferromagnetic material becomes paramagnetic.
Reason (R): Above the Curie temperature, the thermal energy overcomes the magnetic energy that aligns the magnetic dipoles.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The magnetic field inside a solenoid is uniform.
Reason (R): The magnetic field lines inside a solenoid are parallel and equally spaced.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): In a hysteresis loop, the area enclosed represents the energy loss per cycle.
Reason (R): The energy loss in a hysteresis loop is due to the lagging of magnetization behind the magnetizing force.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): A current-carrying conductor placed in a magnetic field experiences a force.
Reason (R): The force on the conductor is due to the interaction of the magnetic field and the magnetic field produced by the current in the conductor.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The magnetic field strength at the center of a current-carrying loop is maximum.
Reason (R): The magnetic field lines are densest at the center of the loop.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): Magnetic materials can be classified as diamagnetic, paramagnetic, and ferromagnetic based on their behavior in a magnetic field.
Reason (R): Diamagnetic materials are repelled by a magnetic field, paramagnetic materials are weakly attracted, and ferromagnetic materials are strongly attracted.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The earth’s magnetic field is not exactly aligned with its rotational axis.
Reason (R): The magnetic poles of the earth do not coincide with its geographic poles.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The strength of a magnetic field at a point is inversely proportional to the square of the distance from the source of the field.
Reason (R): The magnetic field lines spread out as the distance from the source increases.
Answer: Both A and R are true and R is the correct explanation of A. - Assertion (A): The geomagnetic field shields the earth from solar wind.
Reason (R): The geomagnetic field deflects charged particles from the sun.
Answer: Both A and R are true and R is the correct explanation of A.