Which of the following statements are true

A. $\vec{a}$ and $\vec{b}$ are always collinear.

B. Two collinear vectors are always equal in magnitude.

C. Two vectors having the same magnitude are equal

D. Two collinear vectors having the same magnitude and direction are equal.

E. If $\vec{P}$ is a unit vector along line 'l' then the projection of vector $\vec{a}$ on line'l' is given by $\vec{a}.\vec{p}$

Choose the correct answer from the options given below:

D and E only

Check each statement:

A. $\vec{a}$ and $\vec{b}$ are always collinear → False (not all vectors are along the same line)

B. Two collinear vectors are always equal in magnitude → False (they can have different magnitudes)

C. Two vectors having the same magnitude are equal → False (direction may differ)

D. Two collinear vectors having the same magnitude are equal → True (same line and same magnitude implies same vector or opposite; if direction considered, usually they are equal)

E. If $\vec{P}$ is a unit vector along line 'l', then the projection of vector $\vec{a}$ on line 'l' is given by $\vec{a} \cdot \vec{P}$ → True

Answer: D and E