In a compound microscope, the focal length of the objective is 2.5 cm and of eye lens is 5 cm. If an object is placed at 3.75 cm before the objective and the image is […]
If the image formed by a convex mirror of focal length 30 cm is a quarter of the size of the object, then the distance of the object from the mirror will be
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A concave mirror of focal length f₁ is placed at a distance d from a convex lens of focal length f₂. A beam of light coming from infinity and falling on this convex lens concave […]
A ray of light is incident at an angle of incidence i, on one face of a prism of angle A (assumed to be small) and emerges normally from the opposite face. If the refractive […]
The diameter of the eye ball of a normal eye is about 2.5 cm. The power of the eye lens varies from
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(a) 9 D to 8 D (b) 40 D to 32 […]
For having large magnification power of a compound microscope
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(a) length of the microscope tube must be small (b) focal lengths of objective lens and eye-piece should be large. (c) focal lengths […]
The reddish appearance of the sun at sunrise and sunset is due to
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(a) the colour of the sky (b) the scattering of light (c) the polarisation of light (d) the colour […]
For the normal eye, the cornea of eye provides a converging power of 40D and the least converging power of the eye lens behind the cornea is 20D. Using this information, the distance between the […]
The radius of curvature of the convex face of a plano-convex lens is 12 cm and the refractive index of the material of the lens is 1.5. Then, the focal length of the lens is […]
Radii of curvature of a converging lens are in the ratio 1:2. Its focal length is 6 cm and refractive index is 1.5. Then, its radii of curvature are ………… respectively
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(a) […]
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