1.

\(4\vec i.(7\vec i-8\vec j+3\vec k)=\)(A) 4 (B) 28 (C) -32 (D) 124i.(7i - 8j + 3k) =

Answer»

Option : (B) 28 

\(4\hat{i}.(7\hat{i} - 8\hat{j} + 3\hat{k})\)

\(= 28\,\hat{i}.\hat{i} - 32\,\hat{i}.\hat{j} + 12\,\hat{i}.\hat{k}\)

\(= 28(\because \hat{i}.\hat{i} = 1\,\, \&\,\, \hat{i}.\hat{j} = \,\hat{i}.\hat{k} = 0)\)

Option : (B) 28 



Discussion

No Comment Found

Related InterviewSolutions