Date:13/03/2008 URL: http://www.thehindu.com/thehindu/seta/2008/03/13/stories/2008031350111600.htm

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This week’s questions

Why is it that a transistor radio gives a clear and loud reception when the antenna is held or touched by hand?

C. George Varghese, Thrissur, Kerala

Why does sound change continuously as a vessel is being filled up with water from a tap?

K. Aravind, Tiruchi, Tamil Nadu

Why do some cough syrups and shampoos have menthol as one of the ingredients. What is its role in both?

Shreepriya Ponnuraj, Coimbatore,Tamil Nadu

Is there any scientific basis for the belief that one should not sleep with the head pointing towards North due to the adverse effects of the earth’s magnetic field on the human body?

S. Rajagopal, Chennai

The colour of an object depends on the wavelength of the light it reflects. Is there a way to change certain properties of a substance and hence change the colour of the object without changing the wave length of the light reflected by the object?

Ashwin, Hyderabad