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Question

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : The reciprocal lattice of a fcc is a direct lattice of bcc.
Reason (R) : The reciprocal lattice of a bcc is a direct lattice of fcc.
In the light of the above statements, choose the most appropriate answer from the options given below :

This question was previously asked in
CUET PG 2026 Agri-Business Management Question Paper (25-Mar-2026) (Shift 2)
The correct answer is
Both (A) and (R) are correct but (R) is not the correct explanation of (A)

Reciprocal Lattice Assertion (A) Analysis

Assertion (A) states that the reciprocal lattice of a face-centered cubic (fcc) structure is a body-centered cubic (bcc) direct lattice.

  • This statement is correct. The set of reciprocal lattice vectors for an fcc lattice forms a bcc lattice structure.

Reciprocal Lattice Reason (R) Analysis

Reason (R) states that the reciprocal lattice of a body-centered cubic (bcc) structure is a face-centered cubic (fcc) direct lattice.

  • This statement is also correct. The reciprocal lattice corresponding to a bcc direct lattice is an fcc lattice.

Relationship Between Assertion and Reason

Both Assertion (A) and Reason (R) present true statements regarding the relationship between direct and reciprocal lattices of fcc and bcc structures.

  • Assertion (A) describes the reciprocal of fcc.
  • Reason (R) describes the reciprocal of bcc.

While both statements are factually correct, the truth of Reason (R) (reciprocal of bcc is fcc) does not serve as an explanation for the truth of Assertion (A) (reciprocal of fcc is bcc). They are independent, albeit related, crystallographic facts.

Conclusion

Therefore, both statements are correct, but Reason (R) is not the correct explanation for Assertion (A).

The most appropriate answer is: Both (A) and (R) are correct but (R) is not the correct explanation of (A).

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Similar Questions

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  2. The expression $C_V = 3R$ represents :
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Important Questions from Mixed Topic (CUET PG)

  1. Who was the founder of Bolshevik Communist party?
  2. What is the key guide to statecraft in the realist tradition?
  3. Chronologically arrange the events in the Cold War period.
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  4. Morgenthau's principles of political realism are:
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    D. The ethics of international relations is situational ethics which is very different from private morality
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  5. Who among the following political thinkers consider the anarchical self help system to be a compelling factor for States to maximise their relative power positions?

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