161 In monochromatic red light a blue book will probably appear to be_________________? Physics Medium Full question → A black B purple C green D no scientific reasoning available
162 Which one of the following cannot be polarized ? Physics Medium Full question → A radio waves B ultraviolot rays C X-rays D sound waves
163 In a plane polarized light _________________? Physics Medium Full question → A vibration in all direction B vibration in two mutually perpendicular directions C vibration take place in a direction perpendicular to the direction of propagation of light D no vibration at all
164 Wavelength of X-rays falling at glancing angle of 30? on a crystal with atmic spacing 2 x 10-10 for the fist order diffraction is________________? Physics Medium Full question → A 4 x 10-10 m B 2 x 10-10 m C 0.02×10-10m D 20×10-10m
165 When one mirror of a Michelson Interferometer is moved a distance of 0.5 mm we observe 2000 fringes. What will be wavelength of light used ? Physics Medium Full question → A 5000 nm B 5000A C 500m D 2000um
166 The blue colour of the sky is due to___________________? Physics Medium Full question → A diffraction B reflection C polarization D scattering
167 In an interference pattern______________________? Physics Medium Full question → A bright fringes are wider than dark fringes B dark fringes are wider than bright fringe C both dark and bright fringes are of equal width D central fringes are brighter than the outer fringes
168 In Young double slit experiment, if white light is used____________________? Physics Medium Full question → A alternate dark and bright fringes will be seen B coloured fringes will be seen C no interference fringes will be seen D impossible to predict
169 When crest of one wave falls over the trough of the other wave this phenomenon is known as________________? Physics Medium Full question → A polarization B constructive interference C destructive interference D diffraction
170 Which one of the following is nearly monochromatic light ? Physics Medium Full question → A light form fluorescent tube B light form neon lamp C light form sodium lamp D light form simple lamp
171 A point source of light placed in a homogeneous medium gives rise to ___________________? Physics Medium Full question → A a cylindrical wave front B an elliptical wave front C a spherical wave front D a plane wave front
172 Longitudinal waves do not exhibit _____________________? Physics Medium Full question → A reflection B refraction C diffraction D polarization
173 Photoelectric effect was given by ____________________? Physics Medium Full question → A Hertz B Fresnel C Einstein D Plank
174 Which one of the following properties of light does not change with the nature of the medium ? Physics Medium Full question → A velocity B wavelength C amplitude D frequency
175 In double slit experiment we observe _____________________? Physics Medium Full question → A interference fringes only B diffraction fringes only C both interference and diffraction fringes D polirized frringes
176 Optical active crystals rotates the __________________? Physics Medium Full question → A vibrating plane B polarization plane C diffraction plane D interference plane
177 A rubber cord of cross-sectional area 2cm2 has a length of 1m. When a tensile force of 10N is applied the length of the cord increases by 1cm. What is the youngs modulus of rubber ? Physics Medium Full question → A 2×108 Nm-2 B 5×106 Nm-2 C 0.5×10-6 Nm-2 D 0.2×10-6Nm-2
178 What is the SI unit of modulus of elasticity of substance ? Physics Medium Full question → A Nm-2 B Jm-2 C Nm-1 D Being a number it has no unit.
179 Energy needed to magnetize and demagnetize is represented by _________________? Physics Medium Full question → A Hysteresis curve B Hysteresis loop area C Hysteresis loop D Straight line
180 Very weak magnetic fields are detected by___________________? Physics Medium Full question → A Squids B Magnetic resonance imaging (MRI) C Magnetometer D Oscilloscope