Four arrangements to measure temperature of ice in beaker with laboratory thermometer are shown in figure below. Which one of them shows the correct arrangement for accurate measurement of temperature?

Which of the thermometers, $A$ or $B$, will show a greater rise in temperature? Give a reason for your answer.

A circular metal loop is heated at point $O$ as shown in the figure.

In which direction would heat flow in the loop?

In which order the pins at points $P, Q$ and $R$ fixed with the help of wax fall if points $O, P, Q$ and $R$ are equidistant from each other?