Physics Past Questions and Answers

A substance has a half-life of \(3 \mathrm{~min}\). After \(6 \mathrm{~min}\), the count rate was observed to be 400 . What was its count rate at zero time?

A stone and a feather are dropped from the same height above earth surface. Ignoring resistance, which of the following is correct?

An air bubbles rises from the bottom to the top of a water dam which is \(40 \mathrm{~m}\) deep. The volume of the bubble just below the surface is \(2.5 \mathrm{~cm}^{3}\). Find its volume at the bottom of the dam, if atmospheric pressure is equivalent to \(10 \mathrm{~m}\) of water.

When equal weights of iron and water are subjected to an equal supply of heat, if is found that the piece of iron becomes much hotter than water after a shorter time because higher than that of water

Of two identical tuning forks with natural frequency \(256 \mathrm{~Hz}\), one is loaded so that 4 beats per seconds are heard when they are sounded together. What is the frequency of the loaded tuning fork?