165) An object may have varying velocity without having varying speed.
166)  If the universal constant of gravitation were decreasing uniformly with time, then a satellite in orbit would still maintain its                    tangential speed.
167) Radiation emitted by a surface is directly proportional to fourth power of its temperature.
168) Critical temperature in terms of vanderwaal’s constants a & b of a real gas is given by T =8a/27Rb.
169) Slope of an adiabatic curve is always greater than that of an isothermal curve.
170) Radio waves are transverse waves and thus they can be polarised.
171) Two stars cannot give rise to fringes because they are independent sources and thus they cannot be coherent.
172) Coloured spectrum is seen when we look through a muslin cloth, due to diffraction.
173) In a movie, ordinarily 24 frames are projected per second from one end to other of complete film.
174) The sky appears blue, because blue light is scattered the most.
175) The intensity of scattered light varies inversely as fourth power of wavelength i.e. ƛ-4.
176) Golden view of sea shell is due to Polarisation.
177) When a ray of light enters a glass slab from air then its wavelength decreases.
178) As a result of interference of two coherent waves, energy is redistributed and distribution changes with time.
179) The critical angle of light passing from glass to air is minimum for violet light.
180) A diminished virtual image can be produced only with a convex mirror.
181)  Light travels faster in air then in glass according to wave theory of light.
182) To observe diffraction, the size of an obstacle should be of same order as wavelength. Diamagnetic substances possess positive             permeability and negative magnetic susceptibility.
183) Ampere second stands for unit of charge.
184) Above Curie temperature, Ferro magnetic substance becomes paramagnetic.
185) An electron is projected along the axis of a circular conductor carrying some current. Electron will experience no force.
186) Photo cells are used for reproduction of sound from cinema films and automatic switching of street lights.
187)The stopping potential depends on both intensity of incident light and frequency of incident light.
 188)At Curie temperature, ferromagnetic substance becomes paramagnetic.
189)A capacitor is perfect insulator for dielectric current.
190)The quantity of electricity that deposits one gram equivalent of substance is called faraday.