Q.

Light ray incident along a vector AO→ (AO→=2i^-3j^) emerges out along vector OB→ (OB→=Ci^-4j^) as shown in the figure below. The value of C is ______.       [2026]

1 1.6  
2 0.16  
3 11.6  
4 16  

Ans.

(1)

1(AO×j^)⇒(OB×j^)×1.5

2k^13=32[Ck^C2+16]

∴ 413=9C24(C2+16)⇒16C2+256=117C2

256=101C2⇒C=1.59≈1.6