Q: Four students \$A, B, C\$ and \$D\$ looked through pipes of different shapes to see a candle flame as shown in Fig.Who will be able to see the candle flame clearly?

The correct answer is option (d) \$D\$. The tube is straight in fig \$D\$. Therefore, candle flame will be visible clearly to us.

Q: Describe an experiment to show that light travels in a straight line path.

Take three cardboards A, B and C each about \$25 cm\$ square. Take a pin and make a small hole in each cardboard at the same height. Suspend the cardboard pieces by separate threads vertically from a support such that each hole is at the same height, as shown. Pass a string through the holes and pull it taut. This makes the three holes in a straight line. Now take out the string.Place a lighted candle near one of the cardboards (say A). Look at the candle flame from the other side of the cardboard C. The candle flame is clearly seen. Now slightly displace one of the cardboards (say B) so that the holes no longer remain in a straight line. Again look at the candle flame from the other side of the cardboard C. You do not see the candle flame. The reason is that light travels in a straight line and now the holes in the cardboards A, B and C are not in a straight line. Conclusion: Light travels in a straight line path called the rectilinear propagation of light.

Question 1

Explain an experiment to show the rectilinear propagation of light.

Accepted Answer

We take three pieces of cardboard. Place them one on the top of one another and make a hole in the middle of each cardboard by using a thick nail. Erect these cards up on the table at a short distance away from each other. Take a candle which is of the same height as the holes in the cards. Light the candle and place it in front of the cards. We see that the light of the candle is visible only when the holes on cards lie in a straight line. If we disturb them the light of the candle disappears. This experiment shows that light propagates in a straight line.

Question 2

A candle can not be seen through a bent pipe. This shows that

Accepted Answer

Since light travels through a straight line, a candle cannot be seen through a bent pipe.Answer-(D)

Question 3

We can see a non-luminous object when light :

Accepted Answer

We know that a non-luminous object is one that does not emit its own light, although it can still reflect light from other sources. So, we can see a non-luminous object, when light is reflected from the object towards our eyes.

Question 4

The path of light is

Accepted Answer

Toppr Ask Answer

Question 5

Four students $A, B, C$ and $D$ looked through pipes of different shapes to see a candle flame as shown in Fig.Who will be able to see the candle flame clearly?

Accepted Answer

The correct answer is option (d) $D$. The tube is straight in fig $D$. Therefore, candle flame will be visible clearly to us.

Question 6

Describe an experiment to show that light travels in a straight line path.

Accepted Answer

Take three cardboards A, B and C each about $25 cm$ square. Take a pin and make a small hole in each cardboard at the same height. Suspend the cardboard pieces by separate threads vertically from a support such that each hole is at the same height, as shown. Pass a string through the holes and pull it taut. This makes the three holes in a straight line. Now take out the string.Place a lighted candle near one of the cardboards (say A). Look at the candle flame from the other side of the cardboard C. The candle flame is clearly seen. Now slightly displace one of the cardboards (say B) so that the holes no longer remain in a straight line. Again look at the candle flame from the other side of the cardboard C. You do not see the candle flame. The reason is that light travels in a straight line and now the holes in the cardboards A, B and C are not in a straight line. Conclusion: Light travels in a straight line path called the rectilinear propagation of light.

Question 7

Rajesh conducts the following experiment.
He cuts $3$ cardboard pieces, each with a hole in the center, and aligns them in a straight line as shown in the image. He now puts a candle in front of the first cardboard piece and looks at it from behind the third piece. He is able to see the candle. He puts the third cardboard piece aside and now tries to look at the candle. But this time, he is not able to see it.

What can be concluded from this experiment?

Accepted Answer

Light travels in a straight line, called a ray which represents the direction of light propagation until it is not obstructed by some other particles or medium. This phenomenon is called the rectilinear propagation of light.

Question 8

Which property of light is known as rectilinear propagation of light?

Accepted Answer

Light always travels in a straight line.This property of light is known as rectilinear propagation of light.

Question 9

What do we need in order to see a shadow?

Accepted Answer

We need: (i) A source of light, (ii) A screen (iii) An opaque object.

Question 10

We can see the objects only when:

Accepted Answer

Objects can only be seen when light falls onto the object and is reflected back to our eyes to form an image on the retina.

Light Travels in a Straight Line

Language

Rate

REVISE WITH CONCEPTS

Light Travels in Straight Line

Rectilinear Propagation of Light.

Light Preliminaries

QUICK SUMMARY WITH STORIES

Rectilinear Propagation Of Light

How we See Things

A Ray and Beam of Light

Regular and Irregular Reflection

Explain an experiment to show the rectilinear propagation of light.

A candle can not be seen through a bent pipe. This shows that

We can see a non-luminous object when light :

The path of light is

Four students $A, B, C$ and $D$ looked through pipes of different shapes to see a candle flame as shown in Fig.
Who will be able to see the candle flame clearly?

Describe an experiment to show that light travels in a straight line path.

Which property of light is known as rectilinear propagation of light?

What do we need in order to see a shadow?

We can see the objects only when:

Light Travels in a Straight Line

Language

Rate

REVISE WITH CONCEPTS

Light Travels in Straight Line

Rectilinear Propagation of Light.

Light Preliminaries

QUICK SUMMARY WITH STORIES

Rectilinear Propagation Of Light

How we See Things

A Ray and Beam of Light

Regular and Irregular Reflection

Explain an experiment to show the rectilinear propagation of light.

A candle can not be seen through a bent pipe. This shows that

We can see a non-luminous object when light :

The path of light is

Four students A,B,C and D looked through pipes of different shapes to see a candle flame as shown in Fig. Who will be able to see the candle flame clearly?

Describe an experiment to show that light travels in a straight line path.

Which property of light is known as rectilinear propagation of light?

What do we need in order to see a shadow?

We can see the objects only when:

Four students $A, B, C$ and $D$ looked through pipes of different shapes to see a candle flame as shown in Fig.
Who will be able to see the candle flame clearly?