A group of students took an old shoe box and covered it with a black paper from all sides. They fixed a source of light (a torch) at one end of the box by making a hole in it and made another hole on the other side to view the light. They placed a milk sample contained in a beaker/tumbler in the box as shown in the Fig.2.4. They were amazed to see that milk taken in the tumbler was illuminated. They tried the same activity by taking a salt solution but found that light simply passed through it?
Same results were not observed with a salt solution. Explain.

Open in App

Solution

Since salt solution is a true solution and shows no scattering of light while milk is a colloid and when light is scattered from the particles of colloids it is illuminated and it is because of Tyndall effect. In the tyndall effect light is scattered by particles in a colloid or particles in a fine suspension while showing no light in a true solution. It is used to determine whether a mixture is true or colloidal.

Suggest Corrections

Similar questions

A group of students took an old shoe box and covered it with a black paper from all sides. They fixed a source of light (a torch) at one end of the box by making a hole in it and made another hole on the other side to view the light. They placed a milk sample contained in a beaker/tumbler in the box as shown in the Fig.2.4. They were amazed to see that milk taken in the tumbler was illuminated. They tried the same activity by taking a salt solution but found that light simply passed through it?

Explain why the milk sample was illuminated. Name the phenomenon involved.

Can you suggest two more solutions which would show the same effect as shown by the milk solution?

A group of students took an old shoe box and covered it from all sides with black paper. They fixed a source of light (a torch) at one end of the box by making a hole in it and made another hole on the other side to view the light. They placed a milk sample contained in a beaker in between the hole and the torch. They were amazed to see that milk taken in the tumbler was illuminated. They tried the same activity by taking a salt solution but found that light simply passed through it.

Explain why the milk sample was illuminated.Name the phenomenon involved.

pls reply fast

Q. A group of students took an old shoe box and covered it with a black paper from all sides. They fixed a source of light (a torch) at one end of the box by making a hole in it and made another hole on the other side to view the light. They placed a milk sample contained in a beaker/tumbler in the box. They were amazed to see that milk taken in the tumbler was illuminated. They tried the same activity by taking a salt solution but found that light simply passed through it?
(a) Explain why the milk sample was illuminated? Name the phenomenon involved.
(b) Same results were not observed with a salt solution. Explain.
(c) Can you suggest two more solutions which would show the same effect as shown by the milk solution?

Shaunak and Shaurya were feeling bored. They decided to do some activity work. They had learned about pinhole camera and wanted to make one such. They have taken two rectangular boxes that fit into one another without leaving any gap. They decided to cut open one side of each box. Shaunak made a small hole in the larger box at the centre of the closed end opposite the side that has been cut open. Shaurya decided to cut a square of side five centimeters in the smaller box in the closed end opposite the side that has been cut open. They covered this square with tracing paper. Finally, they slide the smaller box into the larger box, ensuring that the pinhole and the tracing paper are in line with one another, but at opposite ends. They slide the smaller box to adjust the focus so that they can capture the image of any objects they want. They were very happy as they had successfully done their work. When they looked through open face of the smaller box, they can see image of object on the screen.

What type of image Shaunak and Shaurya had observed on the screen while they looked through open face of the smaller box?

Join BYJU'S Learning Program