Is a vector necessarily changed if it is rotated through anangle?

Assertion : The resultant acceleration of an ob- ject in circular motion is towards the centre if the speed is constant. Reason : A vector is necessarily changed if it is rotated through an angle.

A vector may change if :

If vector vec i+2vec j+2vec k is rotated through an angle of 90^(@), so as to cross the positivedirection of y-axis,then the vector in the new position is

A dip circle lies initially in the magnetic meridian. If it is now rotated through angle theta in the horizontal plane, then tangent of the angle of dip is changed in the ratio:

A vector is not changed if -

An insect moves in a circular path of radius R. If it rotates through an angle e,find its displacemsementmeans vec s=Deltavec r, where Deltavec r is the change in position vector.

A vector is not changed if

A vector may change when we :