10. Assertion : Graphite is an example of tetragonal crystal system. Reason : For a tetragonal system.

a = b ≠c, α   =  β = 90 °, ϒ = 120 °

a. If both assertion and reason are true and the reason is the correct explanation of the assertion

b. If both assertion and reason are true but reason is not the correct explanation of the assertion

c. If assertion is true but reason is false

d. If the assertion and reason both are false

e. if assertion is false but reason is true.

Ans. d

Explanation : Graphite is hexagonal system  and for tetragonal all three angles are 90°

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