# Assertion Reason Physics Chapter 5 Magnetism and Matter

Questions of Assertion Reason of Physics Chapter 5 Magnetism and Matter CBSE Class 12 are very simple to understand as this chapter deals with Magnetism and Matter. To solve assertion reason type questions of Physics, a deeper understanding of concept about The Bar Magnet, Magnetism and Gauss’s Law, Magnetisation and Magnetic Intensity and Magnetic Properties of Materials is required. In order to help the student in solving Assertion Reason type of questions, detailed process is explained.

How to solve Assertion Reason Type Questions?
In Assertion-Reason type of question, two statements are given, first is Assertion and second is called Reason. Student must have to think critically about both the statements in Assertion Reason Questions, since it combines multiple choice questions and true/false type of questions which requires a higher level of understanding.

How many types are there of Assertion Reason Type Questions?
Assertion-Reason type of questions can be asked either with four MCQ options or with five MCQ options. First four options are same in both the cases only one more options is being provided i.e. last one. One extra option increases the difficulty level of the questions.

In assertion reason type of questions, all 4 or 5 options are same for each question, which are as:

(a) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
(b) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
(c) Assertion (A) is true but reason (R) is false.
(d) Assertion (A) is false but reason (R) is true.
(e) Both Assertion and Reason are false.

Then a question haunts in every student’s mind, which option is correct and when?
This can be understood clearly with the following table:

Assertion (A)Reason (R)MCQ Options (Fixed for all questions)
If TrueTrue(a) Both assertion (A) and reason (R) are true and reason (R) is the correct explanation of assertion (A).
If TrueTrue(b) Both assertion (A) and reason (R) are true but reason (R) is not the correct explanation of assertion (A).
If TrueFalse(c) Assertion (A) is true but reason (R) is false.
If FalseTrue(d) Assertion (A) is false but reason (R) is true.
If FalseFalse(e) Both Assertion and Reason are false.

Now, lets practice some Assertion Reason Questions of Physics: Chapter 5 Magnetism and Matter

For question given below, two statements are given- one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:

(a) Both A and R are true and R is correct explanation of the assertion.
(b) Both A and R are true but R is not the correct explanation of the assertion.
(c) A is true but R is false.
(d) A is false but R is true.

Question.1.
Assertion: We cannot think of a magnetic field configuration with three poles
Reason: A bar magnet does exert a torque on itself due to its own field.

Ans.1. (d)
A is false but R is true.

Question.2.
Assertion: In high latitudes one sees colourful curtains of light hanging down from high altitudes
Reason: The high energy charged particles from the sun are deflected to polar regions by the magnetic field of the earth.

Ans.2. (a)
Both A and R are true and R is correct explanation of the assertion.

Question.3.
Assertion: The true geographic north direction is found by using a compass needle.
Reason: The magnetic meridian of the earth is along the axis of rotation of the earth.

Ans.3. (d)
A is false but R is true.

Question.4.
Assertion: A disc-shaped magnet is deviated above a superconducting material that has been cooled by liquid nitrogen.
Reason: Superconductors repel a magnet.

Ans.4. (a)
Both A and R are true and R is correct explanation of the assertion.

Question.5.
Assertion: Magnetic Resonance Imaging (MRI) is a useful diagnostic tool for producing images of various parts of human body.
Reason: Protons of various tissues of the human body play a role in MRI.

Ans.5. (a)
Both A and R are true and R is correct explanation of the assertion.

Question.6.
Assertion: Diamagnetic materials can exhibit magnetism.
Reason: Diamagnetic materials have permanent magnetic dipole moment.

Ans.6. (c)
A is true but R is false.

Question.7.
Assertion: Ferro-magnetic substances become paramagnetic above Curie temp.
Reason: Domains are destroyed at high temperature.

Ans.7. (a)
Both A and R are true and R is correct explanation of the assertion.

Question.8.
Assertion: If a compass needle be kept at magnetic north pole of the earth the compass needle may stay in any direction.
Reason: Dip needle will stay vertical at the north pole of earth

Ans.8. (b)
Both A and R are true but R is not the correct explanation of the assertion.

Question.9.
Assertion: The ferromagnetic substance do not obey Curie’s law.
Reason: At Curie point a ferromagnetic substance start behaving as a paramagnetic substance.

Ans.9. (b)
Both A and R are true but R is not the correct explanation of the assertion.

Question.10.
Assertion: The ferromagnetic substance do not obey Curie’s law.
Reason: At Curie point a ferromagnetic substance start behaving as a paramagnetic
substance.

Ans.10. (c)
A is true but R is false.

Question.11.
Assertion: A paramagnetic sample display greater magnetisation (for the same magnetic field) when cooled.
Reason: The magnetisation does not depend on temperature.

Ans.11. (d)
A is false but R is true.

Question.12.
Assertion: Electromagnetic are made of soft iron.
Reason: Coercivity of soft iron is small.

Ans.12. (b)
Both A and R are true but R is not the correct explanation of the assertion.

Question.13.
Assertion: The sensitivity of a moving coil galvanometer is increased by placing a suitable magnetic material as a core inside the coil.
Reason: Soft iron has high magnetic permeability and cannot be easily magnetized or demagnetized.

Ans.13. (c)
A is true but R is false.

Question.14.
Assertion: The poles of magnet can not be separated by breaking into two pieces.
Reason: The magnetic moment will be reduced to half when a magnet is broken into two equal pieces.

Ans.14. (b)
Both A and R are true but R is not the correct explanation of the assertion.