Why do we use a perforated plate at the bottom of a pressure cooker?

V. Srinivas Jayapala, Hyderabad

Why is there a humming noise when UPS runs on battery but not during the normal operation?

R.Saranyaraj, Coimbatore, Tamil Nadu

Why are LCD or plasma displays always rectangular in shape?

Ramon Varghese, Pathanamthitta, Kerala

Why don’t we find pigeons on trees?

Ghulam Mehdi Harkari, Kargil, Ladakh

Normally welders feel pain and irritation in the eyes at the end of the day? What causes this?

S.Selva Kumar, Pondicherry

Why does the taste of tea or coffee kept in a thermos flask change when consumed after a few hours?

V.G. Sathyanarayana, Chennai

Is it possible to replace human eyes with cat’s eyes to get day-night vision?

Laxman Phadtare, Thane, Maharashtra

How does depression bring heavy rain?

K. Anaantha Narayanan, Kanyakumari, Tamil Nadu

Is it not possible to generate electricity from wind in a train which is moving at its average speed for a long duration?

N. Arumugam, Tirunelveli, Tamil Nadu