Two plane mirrors are placed at a $120°$ angle with respect to each other. A ray of light is incident upon mirror A at an angle of $70°$ and is reflected toward mirror B. At what angle of reflection does the ray leave the surface of mirror B?

                    

1.  $20°$

2.  $40°$

3.  $50°$

4.  $70°$

A 20 cm object is placed 15 cm in front of a converging lens with a focal length of 10 cm. What is the height and location of the image created by the lens?

1.  The image is 10 cm in size and is located 30 cm behind the lens.

2.  The image is 10 cm in size and is located 20 cm behind the lens.

3.  The image is 20 cm in size and is located 20 cm behind the lens.

4.  The image is 40 cm in size and is located 30 cm behind the lens.

A child stands between two mirrors with his arms out, perpendicular to the mirrors. One plane mirror is 5 m away from his left hand and another plane mirror is 7 m away from his right hand. How far apart are the two images produced by the mirrors if the child has an arm span of 0.5 m?

1.  2 m

2.  12 m

3.  12.5 m

4.  24.5 m

If a ray of light is incident on a plane mirror at an angle 60$°$ from the mirror surface, then deviation produced by the mirror is:

1.  30$°$

2.  60$°$

3.  90$°$

4.  120$°$

The images of clouds and trees in water always less bright than in reality:

1.  because water is forming the image dirty

2.  because there is an optical illusion due to which the image appears to be less bright

3.  because only a portion of the incident light is reflected and quite a large portion goes into water

4.  because the air above the surface of the water contains a lot of moisture

A convex mirror has a focal length = 20 cm. A convergent beam tending to converge to a point 20 cm behind the convex mirror on the principal axis falls on it. The image is formed at:

1.  infinity 

2.  40 cm

3.  20 cm 

4.  10 cm

The largest distance of the image of a real object from a convex mirror of focal length 20 cm can be:

1.   20 cm

2.  infinite

3.  10 cm

4.  depends on the position of the object.

A candle flame of 3 cm is placed at 300 cm from a wall. A concave mirror is kept at distance x from the wall in such a way that the image of the flame on the wall is 9 cm. Then x is:

1.  339 cm 

2.  900 cm

3.  450 cm 

4.  423 cm

A ray of light passes through a plane glass slab of thickness t and refractive index $\mathrm{\mu }$ = 1.5. The angle between the incident ray and emergent ray will be:

1.  0$°$

2.  30$°$

3.  45$°$

4.  60$°$

A fish looking up through the water sees the outside world contained in a circular horizon. lf the refractive index of water is 4/3 and fish is 12 cm below the surface, the radius of the circle in cm is:

1.  $12 \times 3 \times \sqrt{5}$

2.  $4 \times \sqrt{5}$

3.  $12 \times 3 \times \sqrt{7}$

4.  $12 \times 3/\sqrt{7}$