LIGHT REFLECTION AND REFRACTION TEST

3 times magnified and erect image is formed by a concave mirror of focal length 20cm and radius of curvature 40cm. The object is placed between _______cm and __________ cm from the pole

• 0,19.9

• 19.9,20.1

• 20.1,39.9

• 39.9,40.1

An object is moved at constant speed from infinity to the focus of a concave mirror :

• image will move at constant speed from focus to infinity

• image will move slower in the begining and faster later on,away from the mirror

• image will move faster in the begining and slower later on,away from the mirror

• image will move away from the mirror in the begining and towards the mirror later on but with a constant speed

In torches,search lights and headlights of vechicles the buld is placed

• between the pole and the focus of the reflector

• very near to the focus of the reflector

• between the focus and centre of curvature of the reflector

• at the centre of curvature of the reflector

What is used in spectacles ?

• convex mirror

• concave mirror

• convex lens or concave lens

• Neither of above

In the experiment on refraction of light through a rectangular glass slab ABCD ,shown in fig 4.98, The incident ray is _______

Find the size ,nature and position of image formed when an object of size 1cm is placed at a distance of 15cm from a concave mirror of focal length 10cm

Answer explanation

v=-30cm

A beam of light incident on a plane mirror forms a real image on reflection.The incident beam is

• parallel

• convergent

• divergent

• not certain

An object is placed at a distance of 40cm in front of a concave mirror of focal length of 20cm.The image produced is

• virtual and inverted

• real and erect

• real,inverted and of the opposite size as that of the object

• real,inverted and of the same size as that of the object

Image formed by a convex spherical mirror is ?

• virtual

• real

• enlarged

• inverted

Magnification produced by a rear view mirror fitted in vehicles :

• is less than 1

• is more than 1

• is equal to 1

• can be more than or less than one