Light Reflection and Refraction Test

Result

Light Reflection and Refraction Test - 60

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

In the diagram, the correctly marked angles are ______.

A
$$\angle i$$ and $$\angle r$$

B
$$\angle i$$ and $$\angle e$$

C
$$\angle r$$ and $$\angle e$$

D
$$\angle i$$, $$\angle r$$ and $$\angle e$$

Solution

All the angles should be taken from the normal to the ray. So in the figure only $$i$$ and $$r$$ angles are marked with the normal and hence correct.

Angle $$e$$ is marked between the ray and the interface boundary so it is incorrect. Hence option (a) is the answer.
Question 2
1 / -0

Magnification for mirror $$(m) =$$ ______

A
$$\dfrac {v}{u}$$

B
$$\dfrac {u}{v}$$

C
$$\dfrac {h_{o}}{h_{i}}$$

D
$$\dfrac {h_{i}}{h_{o}}$$

Solution

Magnification is ratio of the size of the image $$h_i$$ to the size of the object $$h_o$$.
$$m=\dfrac{h_i}{h_o} = \dfrac{-v}{u}$$ where $$u$$ is object distance and $$v$$ is image distance.
Question 3
1 / -0

For magnification in spherical mirrors object height is :

A
Negative.

B
Positive.

C
For real images positive.

D
For virtual images negative.

Solution

Magnification is the ratio of image size produced by spherical mirrors to the object size. It is the ratio of the height of the image to the height of the object. The height of the object is always positive as the object is always above the principal axis.
Question 4
1 / -0

According to the new cartesian sign convention, the ________ is taken as origin

A
Centre of curvature

B
Pole of the mirror

C
Focus

D
Any point on the principal axis

Solution

According to the new cartesian sign convention, pole of the mirror is taken as the origin. All the measurements of object distance, image distance and the focal length are recorded from the pole of mirror. All measurements are positive in the direction of incident rays whereas that and its opposite measurements are taken as negative.
Question 5
1 / -0

Which of the following is Snell's law?

A
$$n_{1}\sin i = \dfrac {\sin r}{n_{2}}$$

B
$$\dfrac {n_{1}}{n_{2}} = \dfrac {\sin r}{\sin i}$$

C
$$\dfrac {n_{2}}{n_{1}} = \dfrac {\sin r}{\sin i}$$

D
$$n_{2}\sin i = constant$$

Solution

Snell's law of refraction states that the product of sine of angle made by the ray in a medium and the refractive index of that medium is constant i.e. $$n_1\times \sin i = $$ constant
We get $$n_1 \sin i = n_2 \sin r$$
$$\implies$$ $$\dfrac{n_1}{n_2} = \dfrac{\sin r}{\sin i}$$
Question 6
1 / -0

After refraction of light through a glass slab, incident ray and emergent ray are:

A
Perpendicular

B
Parallel

C
In a straight line

D
None of these

Solution

In case of a rectangular glass slab, the refraction takes place at both air-glass interface and glass-air interface. The emergent ray is parallel to the direction of incident ray.
Question 7
1 / -0

An object is placed 25 cm from a convex lens whose focal length is 10 cm. The image distance is ________ .

A
50 cm

B
16.66 cm

C
6.66 cm

D
10 cm

Solution

Given that,

Object distance, $$u=-25cm, Focal\ length, f=10cm$$

From lens formula, $$\dfrac{1}{v}-\dfrac{1}{u}=\dfrac{1}{f}$$

$$\implies \dfrac{1}{v}=\dfrac{1}{f}+\dfrac{1}{u}$$

$$\implies \dfrac{1}{v}=\dfrac{1}{10}-\dfrac{1}{25}$$

$$\implies \dfrac{1}{v}=\dfrac{5-2}{50}=\dfrac{3}{50}$$

$$\implies v=16.66cm$$

Answer-(B)
Question 8
1 / -0

Rays of light are entering from glass to glycerine. If refractive indexes of glass and glycerine are respectively 1.5 and 1.47, find the refractive index of glycerine with respect to glass.

A
0.03

B
1.02

C
2.20

D
0.98

Solution

Absolute refractive index of glass $$n_1 = 1.5$$
Absolute refractive index of glycerine $$n_2 = 1.47$$
R.I. of glass relative index $$n_2 = ?$$
$$ n_{21} \dfrac {n_2}{n_1} = \dfrac {1.47}{1.5} = 0.98 $$
R.I. of glass relative to glycerine is 0.98
Question 9
1 / -0

Why is a Converging lens so called ?

A
The rays of light passing through it meet at a point.

B
The rays of light passing through it pass without any deviation.

C
The rays of light passing through it move away from each other.

D
None of these

Solution

The converging lens focused all parallel rays striking on the converging lens at focus.
Question 10
1 / -0

Consider the following statements :
A real image
1. can be formed on a screen.
2. is always magnified and inverted.
Which of the statements given above is/are correct?

A
Only $$1$$

B
Only $$2$$

C
Both $$1$$ and $$2$$

D
Neither $$1$$ nor $$2$$

Solution

If the image is real then the light will actually converge to form it.
Hence, it can be obtained on a screen.
Hence statement $$1$$ is true.
If the object is at infinity for a concave mirror then it forms a diminished and real image of the object. Hence, statement $$2$$ is false.

User

Question Analysis

Correct -
Wrong -
Skipped -

My Perfomance

Score
-
out of -
Rank
-
out of -

Re-Attempt Weekly Quiz Competition

Light Reflection and Refraction Test - 60

Result

Light Reflection and Refraction Test - 60

Score

-

Rank

-

SHARING IS CARING

Question 1

$$\angle i$$ and $$\angle r$$

$$\angle i$$ and $$\angle e$$

$$\angle r$$ and $$\angle e$$

$$\angle i$$, $$\angle r$$ and $$\angle e$$

Solution

Question 2

$$\dfrac {v}{u}$$

$$\dfrac {u}{v}$$

$$\dfrac {h_{o}}{h_{i}}$$

$$\dfrac {h_{i}}{h_{o}}$$

Solution

Question 3

Negative.

Positive.

For real images positive.

For virtual images negative.

Solution

Question 4

Centre of curvature

Pole of the mirror

Focus

Any point on the principal axis

Solution

Question 5

$$n_{1}\sin i = \dfrac {\sin r}{n_{2}}$$

$$\dfrac {n_{1}}{n_{2}} = \dfrac {\sin r}{\sin i}$$

$$\dfrac {n_{2}}{n_{1}} = \dfrac {\sin r}{\sin i}$$

$$n_{2}\sin i = constant$$

Solution

Question 6

Perpendicular

Parallel

In a straight line

None of these

Solution

Question 7

50 cm

16.66 cm

6.66 cm

10 cm

Solution

Question 8

0.03

1.02

2.20

0.98

Solution

Question 9

The rays of light passing through it meet at a point.

The rays of light passing through it pass without any deviation.

The rays of light passing through it move away from each other.

None of these

Solution

Question 10

Only $$1$$

Only $$2$$

Both $$1$$ and $$2$$

Neither $$1$$ nor $$2$$

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.