Vectors Question 80
Question: A vector $ \overrightarrow{a} $ is turned without a change in its length through a small angle $ d\theta . $ The value of $ |\Delta \overrightarrow{a}| $ and $ \Delta a $ are respectively
Options:
A) $ 0,,a,d\theta $
B) $ a,d\theta ,,0, $
C) 0, 0
D) None of these
Correct Answer: B From the figure $ |\overrightarrow{OA}|,=a $ and $ |\overrightarrow{OB}|,=a $ Also from triangle rule $ \overrightarrow{OB}-\overrightarrow{OA}=\overrightarrow{AB}=\Delta \overrightarrow{a,} $ Therefore AB = a . dq So $ |\Delta \overrightarrow{a,}|,=,a,d\theta $ $ \Delta a $ means change in magnitude of vector i.e. $ |\overrightarrow{OB}|-|\overrightarrow{OA}| $Show Answer
Answer:
Solution:
$ \Rightarrow ,|\Delta \overrightarrow{a,}|,=AB $ Using angle $ =\frac{arc}{radius} $
$ \Rightarrow ,a-a=0 $ So $ \Delta a=0 $
BETA
