A very has magnitude and direction . Does it have a location in space ? Can it very with time ? Will two equal vectors a and b at different locations in space necessarily have identical physical effects ? Give examples in support of your answer .

Answer the following : (i) A vector has magnitude & direction. Does it have a fixed location in space? Can it vary with time. (ii) Will two equal vectors vec(a) & vec(b) at different locations in space necessarily have identical physical effects? (iii) Can three non zero vectors, not in one plane, give a zero resulatnt? Can four vectors do ? (iv) Can a vector have zero magnitude if one of its components is not zero?

Two vectors of equal magnitude 5 unit have an angle 60^0 between them. Find the magnitude of (a) the sum of the vectors and (b) the difference of the vectors. . .

An object has moved through a distance. Can it have zero displacement ? If yes, support your answer with an example.

Can two different compounds have same molecular formula ? Illustrate your answer with two examples.

Precise measurements of physical quantities are a need of science. For example, to ascertain the speed of an aircraft, one must have an accurate method to find its positions at closely separated instants of time. This was the actual motivation behind the discovery of radar in World War II. Think of different examples in modern science you can, give a quantitative idea of the precision needed.

Read each statement below acrefully and state , with reasons and examples , if it is true or false : A scalar quantity is one that (a) is conserved in a process (b) can never take negative values (c ) must be dimensionless (d) does not very from one point to another in space ( e) has the same value for observers with different orientations of axes.