1. This answer was edited.

    Focal length of concave lens (OF1), f = −15 cm Image distance, v = −10 cm According to the lens formula, 1/v – 1/u = 1/f 1/u = 1/v – 1/f = -1/10 – 1/(-15) = -1/10 + 1/15 = -5/150 U = -30 cm The negative value of u indicates that the object is placed 30 cm in front of the lens. Focal length of convexRead more

    Focal length of concave lens (OF1), f = −15 cm
    Image distance, v = −10 cm
    According to the lens formula,
    1/v – 1/u = 1/f
    1/u = 1/v – 1/f = -1/10 – 1/(-15) = -1/10 + 1/15 = -5/150
    U = -30 cm
    The negative value of u indicates that the object is placed 30 cm in front of the lens.

    Focal length of convex mirror, f = +15 cm
    Object distance, u = −10 cm
    According to the mirror formula,
    1/v – 1/u = 1/f
    1/v = 1/f – 1/u = 1/15 + 1/10 = 25/150
    V = 6 cm
    The positive value of v indicates that the image is formed behind the mirror.
    Magnification, m = – Image Distance / Object Distance = – v/u = -6/-10 = +0.6
    The positive value of magnification indicates 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
  2. Focal length of concave lens (OF1), f = −15 cm Image distance, v = −10 cm According to the lens formula, 1/v – 1/u = 1/f 1/u = 1/v – 1/f = -1/10 – 1/(-15) = -1/10 + 1/15 = -5/150 U = -30 cm The negative value of u indicates that the object is placed 30 cm in front of the lens. For more answers visitRead more

    Focal length of concave lens (OF1), f = −15 cm
    Image distance, v = −10 cm
    According to the lens formula,
    1/v – 1/u = 1/f
    1/u = 1/v – 1/f = -1/10 – 1/(-15) = -1/10 + 1/15 = -5/150
    U = -30 cm
    The negative value of u indicates that the object is placed 30 cm in front of the 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 = −25 cm Object height, ho = 5 cm Focal length, f = +10 cm According to the lens formula, 1/v-1/u=1/f 1/v = 1/f + 1/u = 1/10 – 1/25 =15/250 V= 250/15 = 16.66 cm The positive value of v shows that the image is formed at the other side of the lens. Magnification,m = - Image DistanceRead more

    Object distance, u = −25 cm
    Object height, ho = 5 cm
    Focal length, f = +10 cm
    According to the lens formula,
    1/v-1/u=1/f
    1/v = 1/f + 1/u = 1/10 – 1/25 =15/250
    V= 250/15 = 16.66 cm
    The positive value of v shows that the image is formed at the other side of the lens.
    Magnification,m = – Image Distance / Object Distance = – v/u = -16.66 / 25 = -0.66

    The negative sign shows that the image is real and formed behind the lens.
    Magnification,m = Image height / Object height = H₁ / H0 = H₁=5
    H₁ = m X Ho = -0.66 X 5 = -3.3 cm
    The negative value of image height indicates that the image formed is inverted.
    The position, size, and nature of image are shown in the following ray diagram.

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

    See less
    • 1
  4. Case I When the upper half of the lens is covered In this case, a ray of light coming from the object will be refracted by the lower half of the lens. These rays meet at the other side of the lens to form the image of the given object, as shown in the following figure. Case II When the lower half ofRead more

    Case I
    When the upper half of the lens is covered
    In this case, a ray of light coming from the object will be refracted by the lower half of
    the lens. These rays meet at the other side of the lens to form the image of the given
    object, as shown in the following figure.

    Case II
    When the lower half of the lens is covered
    In this case, a ray of light coming from the object is refracted by the upper half of the
    lens. These rays meet at the other side of the lens to form the image of the given object,
    as shown in the following figure.

    See less
    • 1
  5. (a) Concave (b) Convex (c) Concave Explanation (a) Concave mirror is used in the headlights of a car. This is because concave mirrors can produce powerful parallel beam of light when the light source is placed at their principal focus. (b) Convex mirror is used in side/rear view mirror of a vehicle.Read more

    (a) Concave
    (b) Convex
    (c) Concave
    Explanation
    (a) Concave mirror is used in the headlights of a car. This is because concave mirrors can
    produce powerful parallel beam of light when the light source is placed at their principal
    focus.
    (b) Convex mirror is used in side/rear view mirror of a vehicle. Convex mirrors give a
    virtual, erect, and diminished image of the objects placed in front of it. Because of this,
    they have a wide field of view. It enables the driver to see most of the traffic behind
    him/her.
    (c) Concave mirrors are convergent mirrors. That is why they are used to construct solar
    furnaces. Concave mirrors converge the light incident on them at a single point known as
    principal focus. Hence, they can be used to produce a large amount of heat at that point.

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

    See less
    • 1