Q1: A tank painted with which of the following coloured paints, would heat up maximum by radiation from sun ?

ANS:C - Black paint

A tank painted with black paint would heat up the most by radiation from the sun. Black surfaces absorb the most radiant energy across the visible spectrum, as well as in the infrared spectrum. This absorption results in higher heat transfer to the surface, causing the object to heat up more effectively when exposed to sunlight. In contrast, white surfaces reflect most of the incident radiation and absorb less heat, while yellow and grey surfaces fall somewhere in between black and white in terms of absorption and heat retention. Therefore, black paint, by absorbing the most solar radiation, would result in the tank heating up the most when exposed to sunlight.