Find the power of a convex lens if the image formed is at a distance of 25 cm from the lens when the object is placed on the other side of the lens at 12 cm from the optical centre?
A. -4.33 diopters
B. 12.33 diopters
C. -12.33 diopters
D. 4.33 diopters
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Find the power of a convex lens if the image formed is at a distance of 16 cm from the lens when the object is placed on the other side of the lens at 20 cm from the optical centre?
A. -3.75 diopters
B. -11.25 diopters
C. 3.75 diopters
D. 11.25 diopters
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A colour-blind person cannot
A. See distant objects
B. See black colour
C. Distinguish between certain colours
D. Have persistence of vision
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Magnifying Glass is basically a
A. Plano-concave lens
B. Concave lens
C. Convex lens
D. Cylindrical lens
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A microscope used in pathological laboratories forms
A. Magnified, virtual, erect image
B. Diminished, real and erect image
C. Magnified, virtual and inverted image
D. Diminished, virtual and erect image
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Which of the following characteristics of light remains unchanged when light travels from vaccum enters water?
A. Speed
B. Amplitude
C. Frequency
D. Wavelength
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To resolve an object in an electron microscope,
A. The wavelength of the electrons must be close to the diameter of the object
B. The wavelength of the electrons must be greater than the diameter of the object.
C. Both A & B
D. None of the above
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Which of the following is an example of continous emission spectrum?
A. Spectrum of an oil frame
B. Spectrum of a water
C. Both
D. None
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The atmospheric layer reflecting radio waves is called
A. Ozonosphere
B. Ionosphere
C. Stratosphere
D. Mesosphere
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For a ray of light to suffer total internal reflection it has to pass from :
A. Glass to water
B. Water to glass
C. Air to water
D. Air to glass
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Which of the following is optical illusion?
A. Rainbow
B. Earthshine
C. Halo
D. Mirage
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One can distinguish a telescope from a microscope by observing
A. Length
B. Colour
C. Size of the lens
D. Length and size of the lens
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Electron microscope works on which of the following principles?
A. Optical interference
B. Wave Nature of electrons
C. Motion of charged particle in electromagnetic fields
D. Faraday's law of Electromagnetic induction
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Holography is a technique of
A. Recording a permanent, sharp two diimensional black and white or multicolour photograph
B. Recording a permanent three dimensional multicolour photograph
C. Recording a permanent three dimensional black and white photograph
D. Recording a permanent three dimensional photograph of a given single colour or a multicolour
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Optical fiber works on the principle of
A. Scattering
B. Interference
C. Total internal reflection
D. Refraction
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Which one of the following is the correct sequence of passage of light in a compound microscope?
A. Condenser -Objective lens -Eye -piece -Body tube
B. Objective lens -Condenser -Body tube -Eye piece
C. Condenser -Objective lens -Body tube -Eyepiece
D. Eyepiece -Objective lens -Body tube -Mirror
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In a Cinema hall, the distance between the projector and the screen is increased by 2%. Then the intensity of illumination on the screen is
A. Decreased by 2%
B. Decreased by 4%
C. Increased by 2%
D. Increased by 4%
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A simple microscope consists of :
A. A short focus convex lens
B. A long focus convex lens
C. A short focus concave lens
D. A long focus concave lens
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Person who is colourblind cannot distinguish between
A. Black and yellow
B. Red and green
C. Yellow and white
D. Green and blue
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Fiber optics cable used in communication, works on the principle of
A. Regular reflection of light
B. Diffuse reflection of light
C. Refraction of light
D. Total internal reflection of light
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