If \vec{a} =\hat{i} + \hat{j} + \hat{k} and λ=5, what is value of λ\vec{a}?

Category: QuestionsIf \vec{a} =\hat{i} + \hat{j} + \hat{k} and λ=5, what is value of λ\vec{a}?
Editor">Editor Staff asked 11 months ago

If \vec{a} =\hat{i} + \hat{j} + \hat{k} and λ=5, what is value of λ\vec{a}?
 
(a) \hat{i} + \hat{j} + \hat{k}
 
(b) 5\hat{i} + 5\hat{j} + 5\hat{k}
 
(c) \hat{i} + 5\hat{j} + 5\hat{k}
 
(d) 10\hat{i} + 10\hat{j} + 10\hat{k}
 
This question was addressed to me at a job interview.
 
My doubt stems from Multiplication of a Vector by a Scalar in division Vector Algebra of Mathematics – Class 12
NCERT Solutions for Subject Clas 12 Math Select the correct answer from above options 
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1 Answers
Editor">Editor Staff answered 11 months ago

Right option is (b) 5\hat{i} + 5\hat{j} + 5\hat{k}
 
To explain I would say: Multiplication of vector \vec{a} =\hat{i} + \hat{j} + \hat{k} by scalar value 5 results in 5\hat{i} + 5\hat{j} + 5\hat{k}, as in these type of questions we multiply\hat{i}, \hat{j,}
 
\hat{k} with the constant given and the answer comes out to be 5\hat{i} + 5\hat{j} + 5\hat{k}.