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3-1.Vectors
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બે એકમ સદિશનો સરવાળો,એકમ સદિશ હોય, તો તેના બાદબાકી સદિશનું મૂલ્ય શોઘો.
A$\sqrt 2 $
B$\sqrt 3 $
C$1/\sqrt 2 $
D$\sqrt 5 $
Solution
$n_s^2 = n_1^2 + n_2^2 + 2{n_1}{n_2}\cos \theta $$ = 1 + 1 + 2\cos \theta $
$1 = 1 + 1 + 2\cos \theta $
$\cos \theta = – \frac{1}{2}$
$\theta = 120^\circ $
$n_d^2 = n_1^2 + n_2^2 – 2{n_1}{n_2}\cos \theta $$ = 1 + 1 – 2\cos (120^\circ )$
$n_d^2 = 2 – 2( – 1/2) = 2 + 1 = 3$ $ \Rightarrow \,\,{n_d} = \sqrt 3 $
$1 = 1 + 1 + 2\cos \theta $
$\cos \theta = – \frac{1}{2}$
$\theta = 120^\circ $
$n_d^2 = n_1^2 + n_2^2 – 2{n_1}{n_2}\cos \theta $$ = 1 + 1 – 2\cos (120^\circ )$
$n_d^2 = 2 – 2( – 1/2) = 2 + 1 = 3$ $ \Rightarrow \,\,{n_d} = \sqrt 3 $
Standard 11
Physics
