Date:02/07/2009 URL: http://www.thehindu.com/thehindu/seta/2009/07/02/stories/2009070250211300.htm

This week’s questions

Why are aquatic organisms like fish and mosquito larvae not affected by electric shock?

R. Shanmugasundaram, Padappai, Tamil Nadu

Why is sound produced when a train moves over the track? Why is this sound not continuous but in a particular rhythm?

Ramesh Krishnan S., Kottayam, Kerala

What is the role of a starter in a tube light?

Sri Harsha, Visakhapatnam, Andhra Pradesh