1. Power of a lens, P = 1/f (in meters) Power, P = 1.5d F = 1/1.5 = 10/15 = 0.66m A convex lens has a positive focal length. Hence, it is a convex lens or a converging lens. For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-10/

    Power of a lens, P = 1/f (in meters)
    Power, P = 1.5d
    F = 1/1.5 = 10/15 = 0.66m
    A convex lens has a positive focal length. Hence, it is a convex lens or a converging lens.

    For more answers visit to website:
    https://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-10/

    See less
    • 1
  2. Power of a lens, P = 1/f (in meters) P = -2 D f = -1/2 = -0.5m A concave lens has a negative focal length. Hence, it is a concave lens. For more answers visit to website: https://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-10/

    Power of a lens, P = 1/f (in meters)
    P = -2 D
    f = -1/2 = -0.5m
    A concave lens has a negative focal length. Hence, it is a concave lens.

    For more answers visit to website:
    https://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-10/

    See less
    • 1
  3. Object distance, u = −27 cm Object height, h = 7 cm Focal length, f = −18 cm According to the mirror formula, 1/u + 1/v = 1/f 1/v = 1/f – 1/u = -1/18 + 1/27 = -1/54 V = -54 cm The screen should be placed at a distance of 54 cm in front of the given mirror. Magnification, m = - Image Distance/ObjectRead more

    Object distance, u = −27 cm
    Object height, h = 7 cm
    Focal length, f = −18 cm
    According to the mirror formula,
    1/u + 1/v = 1/f
    1/v = 1/f – 1/u = -1/18 + 1/27 = -1/54
    V = -54 cm
    The screen should be placed at a distance of 54 cm in front of the given mirror.
    Magnification, m = – Image Distance/Object Distance = -54/27 = -2
    The negative value of magnification indicates that the image formed is real.
    Magnification, m = Height of the image / Height of the object = h’/h
    h‘ = 7 x (-2) = -14 cm
    The negative value of image height indicates that the image formed is inverted.

    For more answers visit to website:
    https://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-10/

    See less
    • 1
  4. This answer was edited.

    Object distance, u = −20 cm Object height, h = 5 cm Radius of curvature, R = 30 cm Radius of curvature = 2 × Focal length R = 2f f = 15 cm According to the mirror formula, 1/v + 1/u = 1/f 1/v = 1/f – 1/u = 1/15 + 1/20 = 4+3/60 = 7/60 V =8.57 The positive value of v indicates that the image is formedRead more

    Object distance, u = −20 cm
    Object height, h = 5 cm
    Radius of curvature, R = 30 cm
    Radius of curvature = 2 × Focal length
    R = 2f f = 15 cm
    According to the mirror formula,
    1/v + 1/u = 1/f
    1/v = 1/f – 1/u = 1/15 + 1/20 = 4+3/60 = 7/60
    V =8.57
    The positive value of v indicates that the image is formed behind the mirror.
    Magnification, m = – Image Distance/Object Distance = -8.57/-20 = 0.428
    The positive value of Magnification indicates that the image is formed is virtual.
    Magnification, m = Height of the image / Height of the object = h’/h
    h’ m x h = 0.428 x 5 = 2.14 cm
    The positive value of image height indicates that the image formed is erect.
    Therefore, the image formed is virtual, erect, and smaller in size.

    For more answers visit to website:
    https://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-9/

    See less
    • 2
  5. This answer was edited.

    Magnification produced by a mirror is given by the relation Magnification, m = Image height (H₁) / Object height (H0) The magnification produced by a plane mirror is +1. It shows that the image formed by the plane mirror is of the same size as that of the object. The positive sign shows that the imaRead more

    Magnification produced by a mirror is given by the relation

    Magnification, m = Image height (H₁) / Object height (H0)
    The magnification produced by a plane mirror is +1. It shows that the image formed by the plane mirror is of the same size as that of the object. The positive sign shows that the image formed is virtual and erect.

    For more answers visit to website:
    https://www.tiwariacademy.com/ncert-solutions/class-10/science/chapter-9/

    See less
    • 1