Q. 23.7( 4 Votes )
Which one of the following statements is true?
A. A scalar quantity is the one that is conserved in a process.
B. A scalar quantity is the one that can never take negative values.
C. A scalar quantity is the one that does not vary from one point to another in space.
D. A scalar quantity has the same value for observers with different orientations of the axes
We know scalar quantities like the energy of an electron can take a negative value. Also, we have an electric charge which is a scalar quantity and can be negative or positive in nature. Also in some cases where inelastic collision is happening energy is not always conserved. Electric Potential is scalar in nature but varies from one point to another in space.
But, it is always true that scalar quantity has the same value irrespective of from where we observing.
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Motion in two dimensions, in a plane can be studied by expressing position, velocity and acceleration as vectors in Cartesian co-ordinates A = Axî + Ayĵ where î and ĵ are unit vector along x and y directions, respectively and Ax and Ay are corresponding components of (Fig. 4.9). Motion can also be studied by expressing vectors in circular polar co-ordinates as A = Ar + Aɵ where = = cosθ î + sin θ ĵ and = − sin θ î +cos θ ĵ are unit vectors along direction in which ‘r’ and ‘θ ’ are increasing.
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