Question

Compute the median from the following date: Class Marks
(xi)
115 125 135 145 155 165 175 185 195Frequency (fi)
6 25 48 72 116 60 38 22 also find mean and mode

Answer 1

Answer:

172. An Electro magnetic radiation of wavelength 242 nm is just sufficient to ionise a sodium atom. Calculate the ionisation energy of sodium in kJ/mol ? 1) 494.5 2) 594.5 3) 694.5 4) 794.5 173. When a metal is irradiated with light of frequency 4.0 x 1016 s-1 the photo electrons emitted had six times the K.E as the K.E of photo electron emitted when the metal was irradiated with light of frequency 2.0 x 1016s -1 . The calculate the critical frequency of the metal 1) 2.0 x 1016 s-1 2) 1.6 x 1016 s-1 3) 3.0 x 1016 s-1 4) 4.2 x 1016 s-1 174. In photo electric effect, if the energy required to over come the attractive forces on the electron (work function) of Li, Na and Rb are 2.41eV, 2.3 eV and 2.09eV respectively, the work function of “K” could approximately be in eV 1) 2.52 2) 2.2 3) 2.35 4) 2.01 175. In photoelectric effect, the energy of the photon striking a metallic surface is 5.6 x 10-19 J. The kinetic energy of the ejected electrons is 12.0 x 10-20 J. The work function is 1) 6.4 x 10-19 J 2) 6.8 x 10-19 J 3) 4.4 x 10-19 J 4) 6.4 x 10-20 J 176. An Electro magnetic radiation of wavelength 484nm is just sufficient ionise a sodium atom. Calculate the ionisation energy of sodium in kJ/mol approximately ? 1) 494.5 2) 246.9 3) 989.0 4) 794.5 177. Suppose 10-17 J of energy is needed by the interior of human eye to see an object. How many photons of green light   550nm are needed to generate this minimum amount of energy ? 1) 14 2) 28 3) 39 4) 42 178. The ratio of the energies of two different radiations whose frequencies are 3 x 1014 Hz and 5 x 1014 Hz is 1) 3 : 5 2) 5 : 3 3) 3 : 1 4) 5 : 1 179. Which one of the following frequency of radiation (in Hz) has a wavelength of 600nm 1) 2 x 1013 2) 5 x 1016 3) 2 x 1014 4) 5 x 1014 180. What is the energy of photons that corresponds to a wave number of 5 x 10-5 m-1 1) 99.384 x 10-30 J 2) 993.84 x 10-30 J 3) 9.9384 x 10-30 J 4) 0.99384 x 10-30 J vitannitlo evi vaste avi answer cheyyandi