The equation of a wave on a string of linear mass density $0.02\ \text{kg m}^{-1}$ is $Y = 0.01\sin\left[2\pi\left(\dfrac{t}{0.02} - \dfrac{x}{0.50}\right)\right]$ m. The tension in the string is

If charge $+q$ is taken from one point to another over an equipotential surface, then

A charge $Q$ is placed at each corner of a cube of side $r$. The potential at the centre of the cube is ($\epsilon_0$ = permittivity of free space)

Select the 'WRONG' statement about polar molecules.