You must have noticed this common thing in your home, office, or even shops — most ceiling fans have only three blades. While four- or five-blade fans also exist, they are less common in India. Engineers and manufacturers say there are strong scientific and...

Katy Austin,Transport correspondent andPritti Mistry,Business reporterGetty ImagesA new pay-per-mile charge for electric vehicles (EVs) and some hybrid cars was announced in the Budget.All new cars will have to be electric or plug-in hybrid from 2030, when a ban on the sale of new petrol...