Light Reflection and Refraction Test

Result

Light Reflection and Refraction Test - 46

Score
-
out of -
Rank
-
out of -

TIME Taken - -

SHARING IS CARING

If our Website helped you a little, then kindly spread our voice using Social Networks. Spread our word to your readers, friends, teachers, students & all those close ones who deserve to know what you know now.

Weekly Quiz Competition

Question 1
1 / -0

The distance between the extreme points on the periphery of the mirror is called :

A
focal length

B
radius of curvature

C
aperture

D
pole

Solution

The reflecting surface of a spherical mirror has a circular outline. The diameter of the reflecting surface of spherical mirror is called its aperture. It is also the distance between extreme points on the periphery of the mirror.

So option (C) is correct.
Question 2
1 / -0

If we say that the focal length of a spherical mirror is $$n$$ times its radius of curvature, then $$n$$ must be

A
$$2.0$$

B
$$1.5$$

C
$$0.2$$

D
$$0.5$$

Solution

According to the question-
$$f = nR$$
We know the relation between focal length and radius of curvature, which is:
$$R = 2f$$
S0,
$$\Rightarrow f = 0.5 R$$
So, value of $$n$$ is $$0.5$$.
Question 3
1 / -0

A concave mirror is made from a hollow sphere of radius of curvature $$30 cm$$. If an object of height $$2 cm$$ is placed at $$10 cm$$ from the pole of the mirror, determine the size of the image :

A
$$3 cm$$

B
$$6 cm$$

C
$$12 cm$$

D
$$24 cm$$

Solution

Given:
$$u=-10cm$$
$$f=-15cm$$
$$h_{o}=+2cm$$

To find, $$h_{i}$$

From mirror formula,
$$\dfrac{1}{v}+\dfrac{1}{u}=\dfrac{1}{f}$$

$$\Rightarrow\dfrac{1}{v}-\dfrac{1}{10}=-\dfrac{1}{15}$$

$$\Rightarrow \dfrac{1}{v}=\dfrac{1}{10}-\dfrac{1}{15}=\dfrac{5}{150}$$

$$v=+30cm$$

$$magnification=\dfrac{h_{i}}{h_{o}}=\dfrac{-v}{u}$$

$$\dfrac{h_{i}}{+2}=\dfrac{-30}{-10}$$

$$h_{i}=+6cm$$
Question 4
1 / -0

When a ray of light passes from an optically less dense medium to a more dense medium, it :

A
Goes undeviated

B
Bends towards the normal

C
Bends away from the normal

D
Gets reflected

Solution

When a ray of light passes from an optically less dense medium to a more dense medium, it bends towards the normal.
Question 5
1 / -0

A convex lens forms a virtual image of an object placed at $$15 cm$$ from the lens. The focal length of the lens can be

A
$$2 cm$$

B
$$8 cm$$

C
$$15 cm$$

D
$$18 cm$$

Solution

A virtual image of an object is formed by a convex lens only when the object is placed between the lens and the focus. Therefore the focal length of the lens should be greater than the distance of the object from the lens.
Question 6
1 / -0

The middle point of a spherical mirror is called

A
pole

B
centre of sphere

C
centre of curvature

D
none of these

Solution

The centre of the reflecting surface of a spherical mirror is a point called the pole. It lies on the surface of the spherical mirror.
Question 7
1 / -0

An object is placed at 40 cm from the optic centre of a convex lens on its principal axis. if the focal length of the lens is 24 cm, find how far from the lens the screen should be placed to obtain a well-defined image.

A
48 cm

B
38 cm

C
50 cm

D
60 cm

Solution

given: $$u=-40cm$$
$$f=24cm$$
solution:from lens formula
$$\dfrac{1}{v}-\dfrac{1}{u}=\dfrac{1}{f}$$
$$\dfrac{1}{v}+\dfrac{1}{40}=\dfrac{1}{24}$$
$$\dfrac{1}{v}=\dfrac{1}{24}-\dfrac{1}{40}=\dfrac{16}{960}=\dfrac{1}{60}$$
$$v=60cm$$
Question 8
1 / -0

The bending of light ray after passing through a medium is commonly known as :

A
Refraction

B
Scattering

C
Reflection

D
Interference

Solution

Refraction is defined as the phenomenon of bending of light ray when it travels from one medium to another of difefrent refractive index.
Question 9
1 / -0

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

A
Aperture

B
Focal length

C
Principal focus

D
Efficiency

Solution

The aperture of a lens is the length of the surface of the lens exposed for incident light. Focal length is the distance between the focus of the lens and the lens optical center. The principal focus is the focus from which a ray of light traveling parallel to the optical axis passes through or appears to pass through after refraction. There is no term like the efficiency of a lens, but there is a magnification of a lens.
Question 10
1 / -0

The distance between the optical centre of lens and the focal point is called :

A
Reflective index

B
Focal length

C
Radius of curvature

D
Plane of incidence

Solution

Distance between optical centre and focal point of a lens is called focal length.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Light Reflection and Refraction Test - 46

Result

Light Reflection and Refraction Test - 46

Score

-

Rank

-

SHARING IS CARING

Question 1

focal length

radius of curvature

aperture

pole

Solution

Question 2

$$2.0$$

$$1.5$$

$$0.2$$

$$0.5$$

Solution

Question 3

$$3 cm$$

$$6 cm$$

$$12 cm$$

$$24 cm$$

Solution

Question 4

Goes undeviated

Bends towards the normal

Bends away from the normal

Gets reflected

Solution

Question 5

$$2 cm$$

$$8 cm$$

$$15 cm$$

$$18 cm$$

Solution

Question 6

pole

centre of sphere

centre of curvature

none of these

Solution

Question 7

48 cm

38 cm

50 cm

60 cm

Solution

Question 8

Refraction

Scattering

Reflection

Interference

Solution

Question 9

Aperture

Focal length

Principal focus

Efficiency

Solution

Question 10

Reflective index

Focal length

Radius of curvature

Plane of incidence

Solution

User

Question Analysis

My Perfomance

Score

-

Rank

-

Results Announcement on: coming Monday

Stay Tuned: We’ll update you on your result via email or SMS.