[{"id":211465,"question":"A double convex an bubble in water will behave as.","choices":[{"text":"Plane slab","value":"A"},{"text":"Concave mirror","value":"B"},{"text":"Convex lens","value":"C"},{"text":"Concave lens","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":211464,"question":"The image formed on the film of a simple camera is.","choices":[{"text":"Real inverted and diminished","value":"A"},{"text":"Virtual, upright, and diminished","value":"B"},{"text":"Virtual, upright and magnified","value":"C"},{"text":"Real, inverted and magnified","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":211463,"question":"In case of a convex lens, image formed at 2 F is","choices":[{"text":"Virtual, erect and larger than the object","value":"A"},{"text":"Real, inverted and large than the object","value":"B"},{"text":"Real, inverted and same size as the object","value":"C"},{"text":"Real, inverted and smaller than the object","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":211462,"question":"In case of a convex lens when object is placed at 2F image is formed.","choices":[{"text":"At","value":"A"},{"text":"2F","value":"B"},{"text":"away from 2F","value":"C"},{"text":"Between F at and 2 F","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":211461,"question":"In case of a convex lens when object is placed away from 2F, image is formed.","choices":[{"text":"at F","value":"A"},{"text":"at 2F","value":"B"},{"text":"away from 2 F","value":"C"},{"text":"Between F and 2 F","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":211460,"question":"The distance between the optical centre and principal focus is","choices":[{"text":"Focal plane","value":"A"},{"text":"Focal length","value":"B"},{"text":"Optical centre","value":"C"},{"text":"Principal axis","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":211459,"question":"In case of a convex lens the rays closed to and parallel to the principal axis will converge after refraction by the lens at a point.","choices":[{"text":"Optical centre","value":"A"},{"text":"Principal focus","value":"B"},{"text":"Focal plane","value":"C"},{"text":"Principal axis","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":211458,"question":"The line passing symmetrically though the optical center of the lens is.","choices":[{"text":"Focal plane","value":"A"},{"text":"Principal focus","value":"B"},{"text":"Principal axis","value":"C"},{"text":"Focal length","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":211457,"question":"The point midway between the lens surface on its participial axis","choices":[{"text":"Optical centre","value":"A"},{"text":"Principal focus","value":"B"},{"text":"Focal plane","value":"C"},{"text":"Focal length","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":211456,"question":"To obtain is parallel beam from the headlight of a car it must be fitted with.","choices":[{"text":"A convex mirror","value":"A"},{"text":"A concave mirror","value":"B"},{"text":"A convex lens","value":"C"},{"text":"A concave lens","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":211455,"question":"Light entering glass will not suffer change in","choices":[{"text":"Frequency","value":"A"},{"text":"wavelength","value":"B"},{"text":"Speed","value":"C"},{"text":"Direction","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":211454,"question":"The magnifying power of a convex lens of focal length 5 cm is","choices":[{"text":"3","value":"A"},{"text":"5","value":"B"},{"text":"6","value":"C"},{"text":"20","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":211453,"question":"The image of an object 5 mm high is only 1 cm high. The magnification of the lens is","choices":[{"text":"0.2","value":"A"},{"text":"0.5","value":"B"},{"text":"1","value":"C"},{"text":"2","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":211452,"question":"Linear magnification is equal to the ratio of.","choices":[{"text":"Size of the object to the size of the image","value":"A"},{"text":"Size of the image to the size of the object","value":"B"},{"text":"size of the object focal length","value":"C"},{"text":"Size of the image focal length","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":211451,"question":"The power of convex lens of focal length 50 cm will be","choices":[{"text":"1,0 dioptre","value":"A"},{"text":"2.0 dioptre","value":"B"},{"text":"4.0 dioptre","value":"C"},{"text":"5.0 dioptre","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":211450,"question":"The diameter of a lens is called.","choices":[{"text":"Focal length","value":"A"},{"text":"Principal axis","value":"B"},{"text":"Optical centre","value":"C"},{"text":"Aperture","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":211449,"question":"A fixed point inside the lens through which a ray of light does not change its path is called.","choices":[{"text":"Pole","value":"A"},{"text":"Focus","value":"B"},{"text":"Centre of curvature","value":"C"},{"text":"Opticla centre","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":211448,"question":"a spectrometer is used to study","choices":[{"text":"Spectrum","value":"A"},{"text":"Waveform","value":"B"},{"text":"Interference","value":"C"},{"text":"Diffraction","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":211447,"question":"A lens whose thickness is small as compared to focal length is a","choices":[{"text":"Concave lens","value":"A"},{"text":"Double concave lens","value":"B"},{"text":"Convex lens","value":"C"},{"text":"Plano concave lens","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":211446,"question":"Lenses are commonly made of.","choices":[{"text":"Glass only","value":"A"},{"text":"Plastic only","value":"B"},{"text":"Glass and clear plastic","value":"C"},{"text":"Aluminium","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":211445,"question":"The refractive index of benzenes is 1.5 What is the critical angle of benzene.","choices":[{"text":"0.667 <sup>o</sup>","value":"A"},{"text":"42 <sup>o</sup>","value":"B"},{"text":"48<sup>o</sup>","value":"C"},{"text":"90<sup> o</sup>","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":211444,"question":"The phenomenon of total internal reflection occurs in","choices":[{"text":"Optical fibre","value":"A"},{"text":"Rainbow","value":"B"},{"text":"Mirage","value":"C"},{"text":"All of these","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":211443,"question":"The focal length of a thin converging lens is 10 cm What is the maximum distance from the lens that the object can be placed so the lens acts as a magnifying glass.","choices":[{"text":"5 cm","value":"A"},{"text":"10 cm","value":"B"},{"text":"15 cm","value":"C"},{"text":"20 cm","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":211442,"question":"The main advantage of step index fiber is.","choices":[{"text":"The size of the cable","value":"A"},{"text":"The equality of the cbale","value":"B"},{"text":"Difference in the wavelengths of signals","value":"C"},{"text":"All of the above","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":211441,"question":"A negative magnification always means the the image is.","choices":[{"text":"Erect","value":"A"},{"text":"Real","value":"B"},{"text":"Virtual","value":"C"},{"text":"Inverted","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":211440,"question":"Total internal reflection occurs when the angle of incidence is.","choices":[{"text":"Greater than the angle of refraction","value":"A"},{"text":"Equal to the critical angle","value":"B"},{"text":"Greater than the critical angle","value":"C"},{"text":"Greater than 45<sup>o</sup>","value":"D"},{"value":"E"}],"correctAnswer":3},{"id":211439,"question":"The index of refraction for a substance is","choices":[{"text":"Constant","value":"A"},{"text":"Constant for a given wavelwngth","value":"B"},{"text":"Variable with the speed of light","value":"C"},{"text":"Never constant","value":"D"},{"value":"E"}],"correctAnswer":2},{"id":211438,"question":"Telecommunication by Optical fibers is done by","choices":[{"text":"Single mode step index fibre","value":"A"},{"text":"Multimode step index fibre","value":"B"},{"text":"Multimode graded index fibre","value":"C"},{"text":"All of the above","value":"D"},{"value":"E"}],"correctAnswer":4},{"id":211437,"question":"A double convex lens acts as diverging lens when the object is.","choices":[{"text":"Inside the focus","value":"A"},{"text":"At the focus","value":"B"},{"text":"Between F and 4 F","value":"C"},{"text":"a 4F","value":"D"},{"value":"E"}],"correctAnswer":1},{"id":211436,"question":"use of outer layer in optical fires called cladding is mainly to.","choices":[{"text":"Scatter thelight","value":"A"},{"text":"Absorb unwanted light","value":"B"},{"text":"Transmit the light","value":"C"},{"text":"Produce total internal reflection","value":"D"},{"value":"E"}],"correctAnswer":4}]