1. Radius of curvature = 20 cm. We know thatFocal length is equal to half of Radius of curvature. Therefore,Focal length = Radius of curvature / 2 = 20/2 = 10 cm The focal length is10 cm.

    Radius of curvature = 20 cm.
    We know thatFocal length is equal to half of Radius of curvature. Therefore,Focal length = Radius of curvature / 2
    = 20/2
    = 10 cm
    The focal length is10 cm.

    See less
    • 2
  2. The point at whichrays parallel to principal axiscoming from infinity convergeafter being reflected from concave mirroris called the principal focus of concave mirror.

    The point at whichrays parallel to principal axiscoming from infinity convergeafter being reflected from concave mirroris called the principal focus of concave mirror.

    See less
    • 4
  3. Since the student is unable is unable to see faraway object, he is suffering from myopia.In Myopia, the person is unable to see far away clearly but can see near objects clearly. This defect of vision can be corrected by using spectacles having a concave lens of appropriate power.

    Since the student is unable is unable to see faraway object, he is suffering from myopia.In Myopia, the person is unable to see far away clearly but can see near objects clearly. This defect of vision can be corrected by using spectacles having a
    concave lens of appropriate power.

    See less
    • 2
  4. The farthest point where human eye can see is called Far Point of Eye.It is infinity.The nearest Point where human eye can see is called Near Point of Eye.It is 25 cm from the eye.

    The farthest point where human eye can see is called Far Point of Eye.It is infinity.The nearest Point where human eye can see is called Near Point of Eye.It is 25 cm from the eye.

    See less
    • 2
  5. Myopia is defect in which a person is unable to see far objects, but can see near object.It can be corrected with the help of aconcave lensof suitable focal length.

    Myopia is defect in which a person is unable to see far objects, but can see near object.It can be corrected with the help of aconcave lensof suitable focal length.

    See less
    • 2