Question

When the sound travels in the air at 3:40 metre per second find the wavelength of waves in air produced by 20 kilo hertz?

Answer 1

an electric dipole is kept first to the left and then to the right of a negatively charged infinite plane sheet having a uniform surface charge density. The arrows p1 and p2 show the directions of its electric dipole moment in the two cases. Identify for each case, whether the dipole is in stable or unstable equilibrium.