Images

What are images used for?

What are images in computer?

Select the correct equation for magnification of spherical mirrors where $h_i$ is the image height and is $h_o$the object height.

Select the correct statement about magnification of mirror.

An object of height $3 \mathrm{cm}$ kept in front of a concave mirror, gives a real image of size $6 \mathrm{cm}$. The magnification of the mirror is

In the figure given below, there are two convex lenses $L_1$and $L_2$ having focal lengths of $f_1$ and $f_2$, respectively. The distance between $L_1$ and $L_2$ will be equal to the ______of the two foci.

The photograph of a house occupies an area of $1.75 {\mathrm{cm}}^2$ on a $35 \mathrm{mm}$ slide.  The slide is projected on to a screen, and the area of the house on the screen is $1.55 {\mathrm{m}}^2$.  What is the linear magnification of the projector-screen arrangement?

(Answer correct to one decimal place)

A travelling microscope gives the view of meniscus as -

A person sees his virtual image by holding a mirror very close to the face. When he moves the mirror away from his face, the image becomes inverted. What type of mirror he is using?

Assertion : We can't see virtual images from our eyes.

Reason : Virtual image can not be formed on the screen.

Assertion : We can't see virtual images form our eyes.

Reason : Virtual image can not be formed on the screen.

When an object is placed at a distance of $25 \mathrm{cm}$ from a mirror, the magnification is $m_1$. But the magnification becomes $m_2$, when the object is moved $15 \mathrm{cm}$ farther away with respect to the earlier position and $\frac{m_1}{m_2}=4\text{,}$ then find the focal length of the mirror and what type of mirror it is?