Physics Past Questions and Answers

250g of lead at 170<sup style='font-size: smaller;'>o</sup>C is dropped into 100g of water at 0<sup style='font-size: smaller;'>o</sup>C. If the final temperature is 12<sup style='font-size: smaller;'>o</sup>C, the specific heat of lead is (specific heat of water is 4,200J/kg<sup style='font-size: smaller;'>o</sup>C)

An object 15cm high is 30cm from pin-hole camera. If the height of the image formed at the back of the camera is 10cm, the image distance is

The combination of sound waves with different frequencies is known as

Why does a piece of cork float on water?

A rod of length 10cm is heated through 100<sup style='font-size: smaller;'>o</sup>C and its final length is 10.26cm. What is the co-efficient of linear expansion of the rod?