Home
Class 12
PHYSICS
Focal lens of plane convex lens (mu=3/2)...

Focal lens of plane convex lens `(mu=3/2)` is f and radius of curvature of curved surface is R. So write the relation between f and R.

A

f=R

B

f=`R/2`

C

f=2R

D

f=`(3R)/(2)`

Text Solution

Verified by Experts

The correct Answer is:
B, C
From lens maker.s formula,
`1/f=(n-1)(1/R_1-1/R_2)`
`therefore 1/f=(3/2-1)(1/R-(1)/(infty))` (Here `R_1=R` and `R_2=infty`)
`=(1/2)(1/R+0)`
`=1/2xx1/R`
`=(1)/(2R)`
`therefore f=2R`
Promotional Banner

Topper's Solved these Questions

  • RAY OPTICS AND OPTICAL INSTRUMENTS

    KUMAR PRAKASHAN|Exercise SECTION-D (MULTIPLE CHOICE QUESTIONS (MCQs))(MCQs FROM .DARPAN. BASED ON TEXTBOOK)(REFRACTION AND DISPOSION BY PRISM)|14 Videos

  • RAY OPTICS AND OPTICAL INSTRUMENTS

    KUMAR PRAKASHAN|Exercise SECTION-D (MULTIPLE CHOICE QUESTIONS (MCQs))(MCQs FROM .DARPAN. BASED ON TEXTBOOK)(NATURAL PHENOMENA DUE TO SUN LIGHT )|11 Videos

  • RAY OPTICS AND OPTICAL INSTRUMENTS

    KUMAR PRAKASHAN|Exercise SECTION-D (MULTIPLE CHOICE QUESTIONS (MCQs))(MCQs FROM .DARPAN. BASED ON TEXTBOOK)(TOTAL INTERNAL REFLECTION)|14 Videos

  • MOVING CHARGES AND MAGNETISM

    KUMAR PRAKASHAN|Exercise SECTION D (MCQs ASKED IN COMPETITIVE EXAMS)|34 Videos

  • SAMPLE QUESTION PAPER

    KUMAR PRAKASHAN|Exercise PART-B SECTION-C|5 Videos

Similar Questions

Explore conceptually related problems

The adjacent figure shows a thin plano-convex lens of refractive index mu_1 and a thin plano-concave lens of refractive index mu_2 , both having same radius of curvature R of their curved surfaces. The thin lens of refractive index mu_3 has radius of curvature R of both its surfaces. This lens is so placed in between the plano-convex and plano-concave lenses that the plane surfaces are parallel to each other. The focal length of the combination is

Four combinations of two thin lenses are given in List I . The radius of curvature of all curved surfaces is r and the refractive index of all the lenses is 1.5 Match lens combinations in List I with their focal length in List II and select the correct answer using the code given below the lists. (A) (p) 2 r (B) (q) ( r)/(2) ( C) (r) - r (D) (s) r . Code :

In figure , L is half part of an equiconvex glass lens (mu=1.5) whose surfaces have radius of curvature R =40cm and its right surface is silvered . Normal to its principal axis a plane mirror M is placed on right of the lens . Distance between lens L and mirror M is b. A small object O is placed on left of the lens such that there is no parallax between final images formed by the lens and mirror. If transverse length of final image formed by lens is twice that of image formed by the mirror , calculate distance'a' in cm between lens and object.

A plano convex lens of refractive index 1.5 and radius of curvature 30cm. Is silvered at the curved surface. Now this lens has been used to form the image of an object. At what distance from this lens an object be placed in order to have a real image of size of the object.

An object O (real ) is placed at focus of an equi-biconvex lens as shown in. figure-I . The refractive index of lens is mu = 1.5 and the radius of curvature of either suface of lens is R . The lens is surronded by air . In each statement of column-I some changes are made to situation given above and information regarding final image formed as a result is given in column-II . The distance between lens and object is unchanged in all statements of column-I. match the statements in column-I with resulting image in column-II.

List-I gives different lens configurations. The radius of curvature of each surface is R. Rays of light parallel to the axis of lens from left of lens traversing through the lens get focused at distance f from the lens. List-II gives corresponding values of magnitudes of f (mu represent refractive index):-

Calculate equivalent focal length of plano convex lens for following case:- (i) When curved surface is silvered. (ii) When plane surface is silvered.

A plano-convex lens of radius of curvature 30 cm and refractive index 1.5 is kept in air. Find its focal length (in cm).

KUMAR PRAKASHAN-RAY OPTICS AND OPTICAL INSTRUMENTS-SECTION-D (MULTIPLE CHOICE QUESTIONS (MCQs))(MCQs FROM .DARPAN. BASED ON TEXTBOOK)(REFRACTION, MAGNIFICATION, POWER AND COMBINATION OF LENS)
  1. The focal length of an equiconvex lens in air i equal to either of its...

    Text Solution

    |

  2. A concave or convex lens is given such that radii of curvature are sam...

    Text Solution

    |

  3. Focal lens of plane convex lens (mu=3/2) is f and radius of curvature ...

    Text Solution

    |

  4. Radius of curvature of plano-convex lens is 10 cm. If its focal length...

    Text Solution

    |

  5. Radius of curvature of a convex curved surface is 50 cm. If refractive...

    Text Solution

    |

  6. Refractive index of a thin convex lens is 1.5 and radii of curvature i...

    Text Solution

    |

  7. For thin convex lens if magnification is one then object distance and ...

    Text Solution

    |

  8. What is the focal length of lens if the image distance remain same by ...

    Text Solution

    |

  9. Focal length of convex lens for red, green and blue colour are fr , fg...

    Text Solution

    |

  10. Convex lens having focal length f, and concave lens having focal lengt...

    Text Solution

    |

  11. A convex lens is made up of three different materials as shown in figu...

    Text Solution

    |

  12. A convex lens has a focal length f. It is cut inti two parts along the...

    Text Solution

    |

  13. Combination of two convex lenses works always as .......

    Text Solution

    |

  14. One concave and one convex lens have same focal length. If they are ke...

    Text Solution

    |

  15. The medium in which the speed of light is half of the speed in air, if...

    Text Solution

    |

  16. A concave mirror and convex lens (both of refractive index 1.5) have f...

    Text Solution

    |

  17. A convex lens is dipped in a liquid whose refractive index is equal to...

    Text Solution

    |

  18. Convex lens of focal length A and concave lens of focal length B are k...

    Text Solution

    |

  19. Two convex lenses 1 and 2 having focal lengths 25 cm and 30 cm are kep...

    Text Solution

    |

  20. Convex lens having focal length 25 cm and concave lens having focal le...

    Text Solution

    |