1 A person is unable to see an object beyond 30cm Find the

Last updated: 6/24/2023

1 A person is unable to see an object beyond 30cm Find the power of lens in dioptre to correct the vision 10 2 1 3 3 4 2 In a compound microscope the focal length of objective lens is 1 2cm and focal length of eyepiece is 3 0cm When the object is kept at 1 25cm in front of objective the final image is formed at infinity Magnifying power of compound microscope should be nearest to Use D 25cm 1 200 2 100 4 150 w dw o Chapter Ray Optics and Optical Instruments 1 25cm 3 68cm 2 35cm 4 100cm An object O is kept in air in front of a thin plano convex lens of radius of curvature 10cm It s refractive index is and medium towards right of 20 5 10 3 3 400 3 An astronomical telescope consists of two convex lenses If focal length of objective is 1 0m and angular magnification is 10 find the length of the tube between objective and eyepiece such that final image is formed at infinity 1 1 2m 20 3 2 1 1m 3 1 4m 4 1 5m 4 An object is placed at a distance of 15cm from a 8 convex lens of focal length 10cm Find the distance at which a convex mirror of focal length 10cm should be placed on the other side from the lens so that final image coincide with the object itself 1 20cm 2 10cm 3 15cm 4 30cm 20cm 1 60cm to the left of lens 2 12cm to the left of lens 3 60cm to the right of lens 7 Focal length of plano convex glass lens of refractive index 1 5 is 15cm A small object is placed at A as shown The plane surface is silvered The image will be formed at 9 4 30cm to the left of lens 6 A lens made of glass of refractive index 1 5 has focal length 25cm in air It s focal length in water of 4 refractive index will be plane surface is water of refractive index3 What should be the distance x of the object so that the rays become parallel finally Telegram netquestion paper 1 5cm 3 20cm Ratio of dispersive power of lens combination of lenses is 1 2 10cm 4 None of these 00 1 At 20cm from P 3 At 25cm from P 3 A point object O is placed at distance of 15cm from concave morror between a concave and a plane mirror separated by 25cm Considering 1st reflection from concave mirror position of image after 3rd reflection will be Radius of curvature of concave mirror is 20cm 15cm 10cm for achromatic 2 At 30cm from P 4 At 40cm from P