Question 1 :
Lens A produces a magnification of -0.8 whereas lens B produces a magnification of +0.8. Which one of the following applies to lenses A and B?

Question 2 :
Which one of the following materials cannot be used to make a lens?

Question 3 :
Which of the following term is not associated with a lens?

Question 4 :
Convex lens are used in eyeglasses to correct which type of defect?<br>

Question 5 :
If a $3cm$ tall object placed perpendicular to principal axis of a convex lens of focal length $15cm$ produces a real invented image of height $15cm$, then its object distance $(u)$ is ................ and image distance $(v)$ is ................

Question 7 :
Name the lens which always forms an erect and virtual image.<br>

Question 8 :
To construct a ray diagram, you need a minimum of _______ ray(s) whose path(s) after refraction through the lens are known.

Question 9 :
State whether given statement is True or False<br/>A ray of light incident parallel to the principal axis of a lens, passes undeviated after refraction.<br/>

Question 10 :
A camera is an optical instrument which makes use of a :

Question 11 :
A ray passing with which part of a lens emerges undeviated ?

Question 12 :
A printed page is seen through a glass slab place on it. The printed words appear raised. This is due to:

Question 14 :
A convex lens is used to form real image of an object on a screen. It is observed that even when the positions of the object and that screen are fixed are two position of the lens to form real images. If the heights of the images are $4\ cm$ and $9\ cm$ respectively the height of the object is

Question 15 :
An object placed at a distance of <b>16 cm</b> from first principal focus of convex lens, produces a real image at a distance of <b>36 cm </b>from its second principal focus. Then the focal length of the lens is :

Question 16 :
For a thin convex lens when the height of the object is doubled than its image, its object distance is equal to __________.

Question 17 :
<span>What would you use to obtain </span>a real and inverted image for any position of an object ?

Question 18 :
State whether true or false :<div>A transparent material bound by two surfaces, of which one or both surfaces are spherical, forms a lens.</div>

Question 19 :
Suppose you have focused on a screen the image of candle flame placed at the farthest end of the laboratory table using a convex lens. If your teacher suggests you to focus the parallel rays of the sun, reaching your laboratory table, on the same screen, what you are expected to do is to move the:

Question 20 :
There is an equinox lens of focal length of 40 cm. if the lens is cut into two equal parts perpendicular to the principle axis, the focal length of each part will be:

Question 21 :
The image formed by objective lens of compound telescope will be:

Question 22 :
<span>In the table below, column I lists various mirrors and lenses and column II their uses, qualities or properties.</span><div><br/><table class="wysiwyg-table"><tbody><tr><td>column I</td><td>Column II</td></tr><tr><td>I. Plane mirror</td><td>A. Feels thinner in the middle.</td></tr><tr><td>II. Concave mirror</td><td>B. Always forms virtual image.</td></tr><tr><td>III. Convex mirror</td><td>C. Always forms virtual image of smaller size.</td></tr><tr><td>IV. Concave lens </td><td>D. Is used by dentists to examine teeth.</td></tr><tr><td>V. Convex lens</td><td>E. Can be used as reading glass.<br/></td></tr></tbody></table>The correct matching is:</div>

Question 24 :
A point object is placed on the principal axis of the convex lens of focal length 20cm at a distance 40 cm to the left on it. The diameter of the lens is 10cm. If the eye is placed 60cm to the right of the lens at a distance h below the principal axis, then max value of 'h' to see the image is