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Engineering
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A car is fitted with a convex side-view mirror of focal length 20 cm. A second car 2.8 m behind the first car is overtaking the first car at a relative speed of 15 m s-1. The speed of the image of the second car as seen in the mirror of the first one is

  • Option 1)

    \frac{1}{10}ms^{-1}

  • Option 2)

    \frac{1}{15}ms^{-1}

  • Option 3)

    10\: ms^{-1}

  • Option 4)

    15\: ms^{-1}

 
As we learnt in Mirror Formula -   - wherein Object distance from pole of mirror. Image distance from pole of mirror. focal length of the mirror.    From mirror formula so,   Correct option is 2.   Option 1) This is an incorrect option. Option 2) This is the correct option. Option 3) This is an incorrect option. Option 4) This is an incorrect option.
Engineering
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Let the x-z plane be the boundary between two transparent media. Medium 1 in z\geq 0 has a refractive index of \sqrt{2} and medium 2 with z< 0 has a refractive index of \sqrt{3}. . A ray of light in medium 1 given by the vector \vec{A}= 6\sqrt{3}\: \hat{i}+8\sqrt{3}\: \hat{j}-10\: \hat{k} is incident on the plane of separation. The angle of refraction in medium 2 is

  • Option 1)

    30^{\circ}

  • Option 2)

    45^{\circ}

  • Option 3)

    60^{\circ}

  • Option 4)

    75^{\circ}

 
As we learnt in Relation between angle of incidence and angle of refaction -   - wherein refractive index of medium of incidence.   refractive index of medium where rays is refracted. angle of incidence. angle of refraction.     From Snell's law Correct option is 2.   Option 1) This is an incorrect option. Option 2) This is the correct option. Option 3) This is an incorrect...
Engineering
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Direction : The question has a paragraph followed by two statements, Statement-1 and Statement-2. Of the given four alternatives after the statements, choose the one that describes the statements.

A thin air film is formed by putting the convex surface of a plane-convex lens over a plane glass plate. With monochromatic light, this film gives an interference pattern due to light reflected from the top (convex) surface and the bottom (glass plate) surface of the film.

Statement - 1: When light reflects from the air- glass plate interface, the reflected wave suffers a phase change of \pi.

Statement - 2: The centre of the interference pattern is dark.

 

  • Option 1)

    Statement-1 is true, Statement-2 is false.

  • Option 2)

    Statement-1 is true , Statement-2 is true, Statement-2 is the correct explanation of Statement-1.

  • Option 3)

    Statement-1 is true, Statement-2 is true, Statement-2 is not the correct explanation of Statement-1.

  • Option 4)

    Statement-1 is false, Statement-2 is true.

 
As we learnt in Relation between angle of incidence and angle of refaction -   - wherein refractive index of medium of incidence.   refractive index of medium where rays is refracted. angle of incidence. angle of refraction.     Thin lens formula -   - wherein are object and image distance from lens.   S1= When light reflects from denser (glass) a phase drift of  is generated. S2=...
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