Can angle of incidence be equal to the angle refraction? Justify.

Can angle of incidence be equal to the angle refraction? Justify.

Ans: – According to the lens formula when the rays are incident on a plan then in a same plan normal line and reflected rays is present then this phenomenon happened.

What happens to the speed of light when it goes from (i) denser medium to rarer medium (ii) rarer medium to denser medium?

Ans: – The speed of the light will be increase when it travels from denser to rarer medium.

The speed of light will decrease when the light travels from rarer to denser medium.

 

Does a convex lens always converge light? Explain.

Ans: – When the parallel rays are reflected on a convex lens then the rays after passing through it meet to a point after converging so, this convex lens is converging.

 

Write the nature of the image formed by concave lens.

Ans: – The image is virtual, erect and diminished in nature.

 

What will be the nature of the image formed in a convex mirror and in a concave mirror each of focal length 20 cm and object is placed at the distance of 10 cm.

Ans: – From mirror formula, 1/f = 1/v + 1/u;

Here, v=? u=-10cm, f=20cm.

So, 1/20 = 1/v –1/10;

Or, v=6.66cm

Then the image is virtual, diminished in nature.

 

Find the position of the image formed in concave mirror of focal length 12 cm when object is placed 20 cm away from the mirror. Also find magnification.

Ans: – From mirror formula, 1/f = 1/ v + 1/u;

F=12cm, u=-20cm, v=?

So, 1/12 = 1/v – 1/20;

Or, v= 60/8 cm.

Then magnification is (m=-v/u = 60/8 ÷ 20=0.25.

 

In which of the following media, the speed of light is maximum and in which itis minimum. Medium Refractive index

A 1.6

B.1.3

C 1.5

D 1.4.

Ans: – As we know, refractive index= speed of light in air/ speed of light in that medium,

So, which has law refractive index will have more speed of light and then medium B has highest speed of light.

 

The image of a candle formed by a convex lens is obtained on a screen. Will full size of the image be obtained if the lower half of the lens is printed black and completely opaque? Illustrate your answer with a ray diagram.

Ans: – 

 

 

 

 

 

 

 

 

 

Can a single lens ever form a real and erect image?

Ans: – A real and erect image is not possible from a single lens.

 

What is dispersion of light? What is the cause of dispersion of light?

Ans: – Each colour has different refractive index. The dispersion of light is seen when light rays of different refractive index is incident on a surface and reflect in different way.

 

Why do distant object appear to be smaller and closer to each other?

Ans: – The size of object smaller and or larger at a distance depends on the diapers angle because of it the light rays are became when it placed in a distance and diapers angle is smaller.

 

A person looking at a net of crossed wires is able to see the vertical direction more distinctly than the horizontal wires. What is the defect due to? How is such defect of vision corrected?

Ans: – The person looking at a net of crossed wires is able to see the vertical direction more distinctly than the horizontal wires this problem occurs because of the defect of cornea and eye lens and this problem know as astigmatisms.

 

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