Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Consider a ferromagnetic material : Assertion (A) : The individual atoms in a ferromagnetic material possess a magnetic dipole moment and interact with one another in such a way that they spontaneously align themselves forming domains. Reason (R): At high enough temperature, the domain structure of ferromagnetic material disintegrates. Thus, magnetization will disappear at high enough temperature known as Curie temperature. Choose the correct answer from the options given below :

Ferromagnetic material assertion reason question

Q. Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Consider a ferromagnetic material :

Assertion (A): The individual atoms in a ferromagnetic material possess a magnetic dipole moment and interact with one another in such a way that they spontaneously align themselves forming domains.

Reason (R): At high enough temperature, the domain structure of ferromagnetic material disintegrates. Thus, magnetization will disappear at high enough temperature known as Curie temperature.

In the light of the above statements, choose the correct answer from the options given below :

A. (A) is true but (R) is false

B. Both (A) and (R) are true and (R) is the correct explanation of (A)

C. (A) is false but (R) is true

D. Both (A) and (R) are true but (R) is not the correct explanation of (A)

Correct Answer: Both (A) and (R) are true but (R) is not the correct explanation of (A)

Explanation

In ferromagnetic materials, each atom possesses a magnetic dipole moment due to unpaired electron spins.

Because of strong exchange interaction between neighbouring atoms, these magnetic moments tend to align parallel to each other, forming regions called magnetic domains.

Hence, Assertion (A) is true.

At sufficiently high temperature, thermal agitation becomes strong enough to disturb this ordered alignment of magnetic moments.

As a result, the domain structure breaks down and spontaneous magnetization vanishes above a certain temperature called the Curie temperature.

Thus, Reason (R) is also true.

However, Reason (R) explains the effect of temperature on ferromagnetism, not the cause of domain formation mentioned in Assertion (A).

Therefore, although both statements are true, Reason (R) is not the correct explanation of Assertion (A).

Hence, the correct option is

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

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Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R)

Q. Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Consider a ferromagnetic material :

Assertion (A) : The individual atoms in a ferromagnetic material possess a magnetic dipole moment and interact with one another in such a way that they spontaneously align themselves forming domains.

Reason (R): At high enough temperature, the domain structure of ferromagnetic material disintegrates. Thus, magnetization will disappear at high enough temperature known as Curie temperature.

Choose the correct answer from the options given below :

A. (A) is true but (R) is false

B. Both (A) and (R) are true and (R) is the correct explanation of (A)

C. (A) is false but (R) is true

D. Both (A) and (R) are true but (R) is not the correct explanation of (A)

Correct Answer: Both (A) and (R) are true but (R) is not the correct explanation of (A)

Explanation

In a ferromagnetic material, each atom possesses a permanent magnetic dipole moment due to unpaired electron spins.

Because of strong exchange interaction between neighboring atomic magnetic moments, these moments tend to align parallel to each other in small regions called magnetic domains.

This spontaneous alignment of atomic dipoles leading to domain formation correctly supports Assertion (A).

At sufficiently high temperature, thermal agitation becomes strong enough to disturb this ordered alignment of magnetic moments.

As temperature increases beyond a critical value, known as the Curie temperature, the domain structure breaks down and the material loses its ferromagnetic behavior.

This statement correctly describes the temperature dependence of ferromagnetism and hence Reason (R) is also true.

However, Reason (R) explains the destruction of domains at high temperature, whereas Assertion (A) explains the formation of domains due to atomic interactions.

Since Reason (R) does not explain why domains form initially, it is not the correct explanation of Assertion (A).

Therefore, the correct option is

$$ \boxed{\text{Both (A) and (R) are true but (R) is not the correct explanation of (A)}} $$

Explanation

Explanation

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