Inside water, an air bubble behaves………..

The power of a convex lensof focal length 25 cm is………..

A lens does not produce anydeviation of a ray of light passing through………..

The image formed by aconcave lens is always………..

A convex lens forms avirtual image of an object placed………..

When an object is placed at2F₁ of a convex lens, its image is formed………..

To obtain an image of thesame size as that of an object with the help of a convex lens, the objectshould be placed………..

When an object is placedbetween O and F₁ in front of a convex lens, the image formed is………..

When an object is placed atany finite distance from a concave lens, the image is formed ………..

A student obtained a clearimage of window grills on the screen. But the teacher told him to get the imageof a tree far away, instead of the window. To get a clear image, the lens mustbe ……….. (Practice Activity Sheet – 2)

The image obtained while finding the focal length of a convex lens is ………..

Yash found out f₁ andf₂ of a symmetric convex lens experimentally. Then which of thefollowing conclusions is true?

Rays from Sun converge at a point 15 cm in front of a concave mirror. Where should an object be placed so that size ofits image is equal to the size of the object?

A concave mirror of radius 30 cm isplaced in water. Its the focal length in air and water differs by

In order to obtain a magnification of,-0.6 (minus 0.6) with a concave mirror, the object must be placed:

A convex lens of power P is immersed inwater. How will its power change?

Convex mirror is also called

Which position of the object willproduce a magnified virtual image if a concave mirror of focal length 15 cm isbeing used?

If an incident ray passes through the focus, the reflected ray will

Focal length of the plane mirror is

When a ray of light goes from onemedium to another, there is 

For a real object, which of thefollowing can produce a real image?

When the object is placed between f and2f of a convex lens, the image formed is

You are given water, mustard oil,glycerine and kerosene. In which of these media a ray of light incident obliquely at the same angle would bend the most?

The angle between an incident ray andthe plane mirror is 30°. The total angle between the incident ray and reflectedray will be:

Which of the following has the highest refractive index?

Focal length of plane mirror is

Image formed by plane mirror is

A concave mirror gives real, inverted andsame size image if the object is placed

Power of the lens is -40,its focal length is

A concave mirror gives virtual, refractand enlarged image of the object but image of smaller size than the size of theobject is

In optics an object which has higher refractive index is called

The optical phenomena, twinkling of stars,is due to

Convex lens focus a real, point sizedimage at focus, the object is placed

The unit of power of lens is

The radius of curvature of a mirror is 20 cm the focal length is

The magnification producedby a concave lens is positive or negative depending on the object distance.

Due to the light sensitivecells in the eye, we get information about the brightness or dimness of theobject and the colour of the object.

The magnification producedby a convex lens is positive or negative depending on the object distance.

A convex lens always formsa virtual image.