JEE Main202431 Jan 2024Evening ShiftPhysicsMathematics in PhysicsActual
If two vectors A → and B → having equal magnitude R are inclined at an angle θ , then
Options
- AA → − B → = 2 R sin θ 2
- BA → + B → = 2 R sin θ 2
- CA → + B → = 2 R cos θ 2
- DA → − B → = 2 R cos θ 2
Correct answer
C. A → + B → = 2 R cos θ 2
Step-by-step solution
The magnitude of resultant vector A → + B → is given by, R ' = A 2 + B 2 + 2 A B cos θ Here A = B = R Then R ' = R 2 + R 2 + 2 R 2 cos θ = R 2 1 + cos θ = 2 R 2 cos 2 θ 2 = 2 R cos θ 2