The energy of a photo having a wavelength of 10-10m is (h= 6.63 x 10 -34Js, c =3.0 x 10 8ms-1)

The energy of a photon can be calculated using the formula: Energy = Planck's constant × frequency where frequency = speed of light / wavelength. In this question, the wavelength of the photon is given as 10^-10 m, and the values of Planck's constant (h) and the speed of light (c) are also given. So, we can calculate the frequency of the photon as: frequency = c / wavelength = (3.0 x 10^8 m/s) / (10^-10 m) = 3.0 x 10^18 Hz Now, we can use the above formula to calculate the energy of the photon as: Energy = h × frequency = (6.63 x 10^-34 J s) × (3.0 x 10^18 Hz) = 1.89 x 10^-15 J Therefore, the energy of the photon is 1.89 x 10^-15 J, which is closest to option A: 2.0 x 10^-15 J.