Ray Optics & Optical Instruments

Which of the following statements are correct?

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Which of the following statement(s) is/are correct?

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In an experiment with a convex lens, the length of an image is $1\,\text{cm}$, and the object length is $5\,\text{cm}$. If the object is placed at a distance of $40\,\text{cm}$ from the lens, then the focal length of the lens is:

The critical angle of incidence $i_c$ for a ray incident from a denser to rarer medium, is that angle for which:

Which of the following statements are correct?

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If focal length of a concave lens is $50\,\text{cm}$, then the power of the lens would be:

A curved surface $APB$ of radius of curvature $10\,\text{cm}$ separates air ($n_1 = 1$) and a transparent material ($n_2 = 4/3$). A point object $O$ is placed in air on the principal axis of the surface $20\,\text{cm}$ from the pole $P$. The surface is concave towards the rarer medium (center of curvature lies in air, $R = -10\,\text{cm}$). The distance of the image of $O$ from $P$ will be ____________.

For fixed values of radii of curvature of a lens, the power of the lens will be _________________.

The graph correctly representing the variation of image distance $v$ for a convex lens of focal length $f$ versus object distance $u$ is represented by a rectangular hyperbola having asymptotes at $u = f$ and $v = f$ (Option 2).

The refractive index of the material of an equilateral prism is $\sqrt{2}$. The angle of minimum deviation of that prism is _____________.

Lower half of a convex lens is made opaque. Which of the following statement describes the image of the object placed in front of the lens?

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For an astronomical telescope having objective lens of focal length $10\,\text{m}$ and eyepiece lens of focal length $10\,\text{cm}$, the telescope's tube length and magnification respectively are _____________.

Light is travelling from one medium to another medium as given in the options. In which of the following options total internal reflection will be possible?

An astronomical telescope consists of an objective of focal length $50\,\text{cm}$ and eyepiece of focal length $2\,\text{cm}$ is focused on the moon so that the final image is formed at the least distance of distinct vision ($25\,\text{cm}$). Assuming angular diameter of moon as $(1/2)^\circ$ at the objective, the angular size of image is:

A spherical air lens of radii $R_1 = R_2 = 10\,\text{cm}$ is cut from a glass ($\mu = 1.5$) cylinder as shown in the figure. Its focal length is $f_1$. If a liquid of refractive index $2$ is filled in the space, then the focal length of the liquid lens becomes $f_2$. Calculate $f_1$ and $f_2$. Choose the correct options from the following:

Linear magnification produced by a mirror is $+1.5$. Which of the following is correct?

The graph shows the variation of the magnification ($m$) produced by a thin lens with image distance ($v$). The focal length of the lens is:

To increase magnifying power of a refracting type Telescope, we should increase :

The radius of curvature of the curved surface of a plano-convex lens is 20 cm. If the refractive index of the material of the lens be 1.5, then the focal length of the lens will be :

A boy of height 1 m stands in front of a convex mirror. His distance from the mirror is equal to the focal length of the mirror, the height of the image is :